湖南师大附中2014届高三第七次月考数学(理)试题含答案
湖南师大附中2025届高三月考数学(三)试卷及答案
大联考湖南师大附中2025届高三月考试卷(三)数学时量:120分钟满分:150分一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.集合{}0,1,2,3的真子集个数是()A .7B .8C .15D .162.“11x -<”是“240x x -<”的()A .充分不必要条件B .必要不充分条件C .充要条件D .既不充分也不必要条件3.已知角α的终边上有一点P 的坐标是)4,3(a a ,其中0a ≠,则sin2α=()A .43B .725C .2425D .2425-4.设向量a,b 满足+=-=a b a b ,则⋅a b 等于()A .B .2C .5D .85.若无论θ为何值,直线sin cos 10y x θθ⋅+⋅+=与双曲线2215x y m -=总有公共点,则m的取值范围是()A.1m ≥B .01m <≤C .05m <<,且1m ≠D .1m ≥,且5m ≠6.已知函数()2f x 的图象关于原点对称,且满足()()130f x f x ++-=,且当()2,4x ∈时,()()12log 2f x x m =--+,若()()2025112f f -=-,则m 等于()A .13B .23C .23-D .13-7.已知正三棱台111ABC A B C -所有顶点均在半径为5的半球球面上,且AB =11A B =()A .1B .4C .7D .1或78.北宋数学家沈括博学多才、善于观察.据说有一天,他走进一家酒馆,看见一层层垒起的酒坛,不禁想到:“怎么求这些酒坛的总数呢?”经过反复尝试,沈括提出对于上底有ab 个,下底有cd 个,共n 层的堆积物(如图所示),可以用公式()()()2266n nS b d a b d c c a ⎡⎤=++++-⎣⎦求出物体的总数,这就是所谓的“隙积术”,相当于求数列()()(),11,2ab a b a +++.()()()2,,11b a n b n cd ++-+-= 的和.若由小球堆成的上述垛积共7层,小球总个数为238,则该垛积最上层的小球个数为()A .2B .6C .12D .20二、选择题:本题共3小题,每小题6分,共18分.在每小题给出的选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分.9.若()202422024012202412x a a x a x a x +=++++ ,则下列正确的是()A .02024a =B .20240120243a a a +++= C .012320241a a a a a -+-++= D .12320242320242024a a a a -+--=- 10.对于函数()sin cos f x x x =+和()sin cos 22g x x x ππ⎛⎫⎛⎫=--- ⎪ ⎪⎝⎭⎝⎭,下列说法中正确的有()A .()f x 与()g x 有相同的零点B .()f x 与()g x 有相同的最大值点C .()f x 与()g x 有相同的最小正周期D .()f x 与()g x 的图象有相同的对称轴11.过点()0,2P 的直线与抛物线2:4C x y =交于()()1122,,,A x y B x y 两点,抛物线C 在点A 处的切线与直线2y =-交于点N ,作NM AP ⊥交AB 于点M ,则()A .5OA OB ⋅=-B .直线MN 恒过定点C .点M 的轨迹方程是()()22110y x y -+=≠D .AB MN选择题答题卡题号1234567891011得分答案三、填空题:本题共3小题,每小题5分,共15分.12.已知复数12,z z 的模长为1,且21111z z +=,则12z z +=_____.13.在ABC 中,角,,A B C 所对的边分别为,,a b c 已知5,4a b ==,()31cos 32A B -=,则sin B =_____.14.若正实数1x 是函数()2e e x f x x x =--的一个零点,2x 是函数()g x =()()3e ln 1e x x ---的一个大于e 的零点,则()122e ex x -的值为_____.四、解答题:本题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.15.(本小题满分13分)现有某企业计划用10年的时间进行技术革新,有两种方案:贷款利润A 方案一次性向银行贷款10万元第1年利润1万元,以后每年比前一年增加25%的利润B 方案每年初向银行贷款1万元第1年利润1万元,以后每年比前一年增加利润3000元两方案使用期都是10年,贷款10年后一次性还本付息(年末结息),若银行贷款利息均按10%的复利计算.(1)计算10年后,A 方案到期一次性需要付银行多少本息?(2)试比较A B 、两方案的优劣.(结果精确到万元,参考数据:10101.1 2.594,1.259.313≈≈)如图,四棱锥P ABCD -中,底面ABCD 为等腰梯形,22AD AB BC ==2=.点P 在底面的射影点Q 在线段AC 上.(1)在图中过A 作平面PCD 的垂线段,H 为垂足,并给出严谨的作图过程;(2)若2PA PD ==.求平面PAB 与平面PCD 所成锐二面角的余弦值.已知函数()()e sin cos ,x f x x x f x =+-'为()f x 的导数.(1)证明:当0x ≥时,()2f x '≥;(2)设()()21g x f x x =--,证明:()g x 有且仅有2个零点.在平面直角坐标系xOy 中,已知椭圆()2222:10x y C a b a b +=>>的两个焦点为12,F F P、为椭圆C 上一动点,设12F PF ∠θ=,当23πθ=时,12F PF ∆.(1)求椭圆C 的标准方程.(2)过点()0,2B 的直线l 与椭圆交于不同的两点(M N M 、在,B N 之间),若Q 为椭圆C上一点,且OQ OM ON =+,①求OBM OBNSS ∆∆的取值范围;②求四边形OMQN 的面积.飞行棋是大家熟悉的棋类游戏,玩家通过投掷骰子来决定飞机起飞与飞行的步数.当且仅当玩家投掷出6点时,飞机才能起飞.并且掷得6点的游戏者可以连续投掷骰子,直至显示点数不是6点.飞机起飞后,飞行步数即骰子向上的点数.(1)求甲玩家第一轮投掷中,投掷次数X 的均值()()1(k E X kP k ∞===∑()1lim n n k kP k ∞→=⎫⎛⎫⎪ ⎪⎝⎭⎭∑;(2)对于两个离散型随机变量,ξη,我们将其可能出现的结果作为一个有序数对,类似于离散型随机变量的分布列,我们可以用如下表格来表示这个有序数对的概率分布:(记()()()()()(1211,,mni i i j j j i j i p x p x p x y p y p y p x ξη========∑∑,)j y .)ξη1x 2x ...n X 1y ()11,p x y ()21,p x y ...()1,n p x y ()21p y 2y ()12,p x y ()22,p x y ...()2,n p x y ()22p y ...⋯⋯...⋯...my ()1,m p x y ()2,m p x y ...(),n m p x y ()2m p y ()11p x ()12p x ...()1n p x 1若已知i x ξ=,则事件{}j y η=的条件概率为{}j i P y x ηξ===∣{}{}()()1,,j i i j i i P y x p x y P x p x ηξξ====.可以发现i x ηξ=∣依然是一个随机变量,可以对其求期望{}{}()111mi j j i j i E x y P y x p x ηξηξ===⋅===∑∣∣.()1,mj i j j y p x y =∑(i )上述期望依旧是一个随机变量(ξ取值不同时,期望也不同),不妨记为{}E ηξ∣,求{}E E ηξ⎡⎤⎣⎦∣;(ii )若修改游戏规则,需连续掷出两次6点飞机才能起飞,记0ξ=表示“甲第一次未能掷出6点”,1ξ=表示“甲第一次掷出6点且第二次未能掷出6点”,2ξ=表示“甲第一次第二次均掷出6点”,η为甲首次使得飞机起飞时抛掷骰子的次数,求E η.炎德・英才大联考湖南师大附中2025届高三月考试卷(三)数学参考答案题号1234567891011答案C A C B B D A B BC ACD BC一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.C 【解析】集合{}0,1,2,3共有42115-=(个)真子集.故选C .2.A 【解析】解不等式240x x -<,得04x <<,解不等式11x -<,得02x <<,所以“11x -<”是“240x x -<”的充分不必要条件.3.C 【解析】根据三角函数的概念,2442sin cos 2tan 24tan ,sin23311tan 25y a x a αααααα======+,故选C .4.B 【解析】()()()22111911244⎡⎤⋅=+--=-=⎣⎦a b a b a b .5.B 【解析】易得原点到直线的距离1d ==,故直线为单位圆的切线,由于直线与双曲线2215x y m -=总有公共点,所以点()1,0±必在双曲线内或双曲线上,则01m <≤.6.D 【解析】依题意函数()f x 的图象关于原点对称,所以()f x 为奇函数,因为()()()133f x f x f x +=--=-,故函数()f x 的周期为4,则()()20251f f =,而()()11f f -=-,所以由()()2025112f f -=-可得()113f =,而()()13f f =-,所以()121log 323m --=,解得13m =-.7.A 【解析】上下底面所在外接圆的半径分别为123,4r r ==,过点112,,,A A O O 的截面如图:22222121534,543,1OO OO h OO OO =-==-∴=-=,故选A .8.B 【解析】由题意,得6,6c a d b =+=+,则由()()()772223866b d a b d c c a ⎡⎤++++-=⎣⎦得()()7[26212(6b b a b b a ++++++6)]()762386a a ++-=,整理得()321ab a b ++=,所以773aba b +=-<.因为,a b 为正整数,所以3ab =或6.因此有6,3a b ab +=⎧⎨=⎩或5,6.a b ab +=⎧⎨=⎩而63a b ab +=⎧⎨=⎩无整数解,因此6ab =.故选B .二、选择题:本题共3小题,每小题6分,共18分.在每小题给出的选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分.9.BC 【解析】对于A :令0x =,则01a =,故A 错误;对于B :令1x =,则20240120243a a a +++= ,故B 正确;对于C :令1x =-,则012320241a a a a a -+-++= ,故C 正确;对于D ,由()202422024012202412x a a x a x a x +=++++ ,两边同时求导得()20232202312320242024212232024x a a x a x a x ⨯⨯+=++++ ,令1x =-,则12320242320244048a a a a -++-=- ,故D 错误.故选BC .10.ACD 【解析】()()32sin ,2sin 2sin 4244f x x g x x x ππππ⎛⎫⎛⎫⎛⎫=+=--=- ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭.令()0f x =,则,4x k k ππ=-+∈Z ;令()0g x =,则3,4x k k ππ=+∈Z ,两个函数的零点是相同的,故选项A 正确.()f x 的最大值点是()2,,4k k g x ππ+∈Z 的最大值点是32,4k k ππ-+∈Z ,两个函数的最大值虽然是相同的,但最大值点是不同的,故选项B 不正确.由正弦型函数的最小正周期为2πω可知()f x 与()g x 有相同的最小正周期2π,故选项C 正确.曲线()y f x =的对称轴为,4x k k ππ=+∈Z ,曲线()y g x =的对称轴为5,4x k k ππ=+∈Z ,两个函数的图象有相同的对称轴,故选项D 正确.故选ACD.设直线AB 的方程为2y tx =+(斜率显然存在),221212,,,44x x A x B x ⎛⎫⎛⎫ ⎪ ⎪⎝⎭⎝⎭,联立22,4,y tx x y =+⎧⎨=⎩消去x 整理可得2480x tx --=,由韦达定理得12124,8x x t x x +==-,A .22121212124,84444x x y y OA OB x x y y =⋅=⋅=+=-+=- ,故A 错误;B .抛物线C 在点A 处的切线为21124x x x y ⎛⎫=+ ⎪⎝⎭,当2y =-时,11121244282222x x x x x t x x =-=-=+=-,即()2,2N t -,直线MN 的方程为()122y x t t +=--,整理得xy t=-,直线MN 恒过定点(0,0),故B 正确;C .由选项B 可得点M 在以线段OP 为直径的圆上,点O 除外,故点M 的轨迹方程是()()22110y x y -+=≠,故C 正确;D.222t MN +==,AB =则()2221412222t AB MNt +⎫==+,,m m =≥则12ABm MN m ⎛⎫=- ⎪⎝⎭,设()1,f m m m m =-≥,则()2110f m m=+>',当m ≥,()f m 单调递增,所以()min f m f==,故D 错误.故选BC .三、填空题:本题共3小题,每小题5分,共15分.12.1【解析】设()()12i ,,i ,z a b a b z c d c d =+∈=+∈R R ,因为21111z z +=,所以2122111z zz z z z +=.因为11221,1z z z z ==,所以121z z +=,所以()()i i i 1a b c d a c b d -+-=+-+=,所以1,0a c b d +=+=,所以()()12i 1z z a c b d +=+++=.13.74【解析】在ABC 中,因为a b >,所以A B >.又()31cos 32A B -=,可知A B-为锐角且()sin 32A B -=.由正弦定理,sin 5sin 4A aB b ==,于是()()()5sin sin sin sin cos cos sin 4B A A B B A B B A B B ⎡⎤==-+=-+-⎣⎦.将()cos A B -及()sin AB -的值代入可得3sin B B =,平方得2229sin 7cos 77sin B B B ==-,故7sin 4B =.14.e 【解析】依题意得,1211e e 0x x x --=,即()()12311122e e ,0,e ln 1e 0x x x x x x -=>---=,即()()3222e ln 1e ,e x x x --=>,()()()131122e e e e ln 1x x x x x ∴-==--,()()()()()()211ln 111112212e e ln 1e ,e e ln 1e e x x x x x x x x -+++⎡⎤∴-=--∴-=--⎣⎦,又22ln 1,ln 10,x x >->∴ 同构函数:()()1e e ,0x F x x x +=->,则()()312ln 1e F x F x =-=,又()()111e e e e e 1e x x x x F x x x +++=-+=-+',00,e e 1,e 10x x x >∴>=∴-> ,又()()1e 0,0,x x F x F x +>'>∴单调递增,()()()3122212222e ln 1e e ln 1,e e e ex x x x x x ---∴=-∴===.四、解答题:本题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.15.【解析】(1)A 方案到期时银行贷款本息为()1010110%26⨯+≈(万元).……(3分)(2)A 方案10年共获利:()()1091.2511125%125%33.31.251-+++++=≈- (万元),……(5分)到期时银行贷款本息为()1010110%25.9⨯+≈(万元),所以A 方案净收益为:33.325.97-≈(万元),……(7分)B 方案10年共获利:()()101010.31 1.3190.310123.52⨯-⨯++++⨯=⨯+= (万元),……(9分)到期时银行贷款本息为()()()()101091.11.11110%110%110%17.51.11-++++++=≈- (万元),……(11分)所以B 方案净收益为:23.517.56-≈(万元),……(12分)由比较知A 方案比B 方案更优.……(13分)16.【解析】(1)连接PQ ,有PQ ⊥平面ABCD ,所以PQ CD ⊥.在ACD 中,2222cos 54cos AC AD CD AD CD ADC ADC ∠∠=+-⋅⋅=-.同理,在ABC 中,有222cos AC ABC ∠=-.又因为180ABC ADC ∠∠+= ,所以()1cos ,0,1802ADC ADC ∠∠=∈ ,所以60ADC ∠= ,3AC =故222AC CD AD +=,即AC CD ⊥.又因为,,PQ AC Q PQ AC ⋂=⊂平面PAC ,所以CD ⊥平面PAC .CD ⊂平面PCD ,所以平面PCD ⊥平面PAC .……(5分)过A 作AH 垂直PC 于点H ,因为平面PCD ⊥平面PAC ,平面PCD ⋂平面PAC PC =,且AH ⊂平面PAC ,有AH ⊥平面PCD .……(7分)(2)依题意,22AQ PA PQ DQ =-=.故Q 为,AC BD 的交点,且2AQ ADCQ BC==.所以2222326,333AQ AC PQ PA AQ ===-.过C 作直线PQ 的平行线l ,则,,l AC CD 两两垂直,以C 为原点建立如图所示空间直角坐标系,则:()()36131,0,0,0,,0,3,0,,,03322D P A B ⎛⎫⎛⎫- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭,所以()326232613261,0,0,0,,0,,,,,3333263CD CP AP BP ⎛⎛⎛===-=- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭ .设平面PCD 的法向量为(),,x y z =m ,则()0,0,3CD x CP y ⎧⋅==⎪⎨⋅=+=⎪⎩m m取()0,=-m .同理,平面PAB的法向量)1=-n ,1cos<,3⋅>==m n m n m n ……(14分)故所求锐二面角余弦值为13.……(15分)17.【解析】(1)由()e cos sin x f x x x =++',设()e cos sin x h x x x =++,则()e sin cos x h x x x '=-+,当0x ≥时,设()()e 1,sin x p x x q x x x =--=-,()()e 10,1cos 0x p x q x x ''=-≥=-≥ ,()p x ∴和()q x 在[)0,∞+上单调递增,()()()()00,00p x p q x q ∴≥=≥=,∴当0x ≥时,e 1,sin x x x x ≥+≥,则()()()e sin cos 1sin cos sin 1cos 0x h x x x x x x x x x '=-+≥+-+=-++≥,∴函数()e cos sin x h x x x =++在[)0,∞+上单调递增,()()02h x h ∴≥=,即当0x ≥时,()2f x '≥.……(7分)(2)由已知得()e sin cos 21x g x x x x =+---.①当0x ≥时,()()()e cos sin 220,x g x x x f x g x ≥''=++-=-∴ 在[)0,∞+上单调递增,又()()010,e 20g g πππ=-<=->∴ 由零点存在定理可知,()g x 在[)0,∞+上仅有一个零点.……(10分)②当0x <时,设()()2sin cos 0e x x xm x x --=<,则()()2sin 10exx m x '-=≤,()m x ∴在(),0∞-上单调递减,()()01m x m ∴>=,()e cos sin 20,e cos sin 20x x x x g x x x '∴++-<∴=++-<,()g x ∴在(),0∞-上单调递减,又()()010,e 20g g πππ-=-<-=+> ,∴由零点存在定理可知()g x 在(),0∞-上仅有一个零点,综上所述,()g x 有且仅有2个零点.……(15分)18.【解析】(1)设()00,,P x y c 为椭圆C 的焦半距,12122F PF p S c y ∆=⋅⋅,00y b <≤ ,当0y b =时,12F PF S 最大,此时()0,P b 或()0,P b -,不妨设()0,P b ,当23πθ=时,得213OPF OPF π∠∠==,所以c =,又因为12F PF S bc ∆==,所以1,b c ==从而2,a =∴椭圆C 的标准方程为2214x y +=.……(3分)(2)由题意,直线l 的斜率显然存在.设()()1122: 2.,,,l y kx M x y N x y =+.……(4分)1112OBM S OB x x ∆∴=⋅=,同理,2OBN S x ∆=.12OBM OBN S xS x ∆∆∴= (6))联立()22222,141612044y kx k x kx x y =+⎧⇒+++=⎨+=⎩,……(8分)()()()22223164121416430,4k k k k ∴∆=-⨯⨯+=->∴>.……(9分)又121212221612,0,,1414k x x x x x x k k-+==>∴++ 同号.()()2222122121212216641421231414k x x x x k k x x x x kk-⎛⎫ ⎪++⎝⎭∴===+++.()22212122364641616,4,,42143331434x x k k x x k k ⎛⎫>∴=∈∴<++< ⎪⎛⎫+⎝⎭+ ⎪⎝⎭ .令()120x x λλ=≠,则116423λλ<++<,解得()()11,11,3,,11,333OBM OBN S S λ∆∆⎛⎫⎛⎫∈∴∈ ⎪ ⎪⎝⎭⎝⎭ .……(12分)(3)()1212,,OQ OM ON Q x x y y =+∴++.且四边形OMQN 为平行四边形.由(2)知()12121222164,41414k x x y y k x x k k-+=∴+=++=++,22164,1414kQ k k -⎛⎫∴ ⎪++⎝⎭.而Q 在椭圆C 上,2222164441414k k k -⎛⎫⎛⎫∴+⨯= ⎪ ⎪++⎝⎭⎝⎭.化简得2154k =.……(14分)∴线段161219357115224MN ==⋅+,……(15分)O到直线MN的距离d == (16))OMQN 574S MN d ∴=⋅=四边形.……(17分)19.【解析】(1)()115,1,2,3,66k P X k k -⎛⎫==⨯= ⎪⎝⎭ ,所以()()215111,1,2,3,,5126666nk n k k k P X k k kP k n =⎛⎫⋅====⨯+⨯+⨯ ⎪⎝⎭∑ ,记211112666n n S n =⨯+⨯++⨯ ,则2311111126666n n S n +=⨯+⨯++⨯ .作差得:1211111511111111661666666556616nn n n n n n S n n ++⎛⎫- ⎪⎛⎫⎛⎫⎝⎭=+++-⨯=-⨯=-+ ⎪⎪⎝⎭⎝⎭- ,所以()16111661,555566556n nn n n k n S kP k S n =⎡⎤⎛⎫⎛⎫⎛⎫⎛⎫=⋅-+==-+⎢⎥ ⎪⎪ ⎪⎪⎝⎭⎝⎭⎝⎭⎝⎭⎢⎥⎣⎦∑.故()()()116616lim lim 5565nn n n k k E X kP k kP k n ∞∞∞→→==⎡⎤⎛⎫⎛⎫⎛⎫===-+=⎢⎥ ⎪ ⎪⎪⎝⎭⎝⎭⎝⎭⎢⎥⎣⎦∑∑.……(6分)(2)(i ){}E ηξ∣所有可能的取值为:{},1,2,,i E x i n ηξ== ∣.且对应的概率{}{}()()()1,1,2,,i i i p E E x p x p x i n ηξηξξ====== ∣∣.所以{}{}()()()()()111111111,,,nnmn m i i j i j i j i j i i j i j i E E E x p x y p x y p x y p x y p x ηξηξ=====⎛⎫⎡⎤==⋅=⋅= ⎪⎣⎦ ⎪⎝⎭∑∑∑∑∑∣∣又()()()()21111111,,,nmmnmn mj i j j i j j i j j j i j j i j i j y p x y y p x y y p x y y p y E η=======⎛⎫⋅=⋅==⋅= ⎪⎝⎭∑∑∑∑∑∑∑,所以{}E E E ηξη⎡⎤=⎣⎦∣.……(12分)(ii ){}{}{}12355101,;12,;22,63636E E p E E p E p ηξηηξηη==+===+====∣∣,{}()()5513542122636363636E E E E E ηηξηηη⎡⎤==++++⨯=+⎣⎦∣,故42E η=.……(17分)。
湖南省师大附中2014届高三物理上学期第一次月考试题(含解析)新人教版
湖南师大附中2014届高三第一次月考物理试题〔考试范围:运动学、相互作用、牛顿运动定律〕本试题卷分选择题和非选择题两局部,时量90分钟,总分为110分。
第1卷选择题〔共48分〕一、选择题〔本大题共l2小题,每一小题4分,总分为48分。
有的小题只有一个选项符合题意,有的小题有几选项符合题意,请将符合题意的选项的序号填入答题表格中〕1.一个作自由落体运动的物体,从开始运动起通过连续三段距离的时间分别是t、2t、3t,这三段距离之比为A.1:23:33B.1:22:33C.1:2:3 D.1:3:5 2.物体静止于倾角为θ的斜面上,当斜面倾角θ缓缓减小时,物体所受力的变化情况是A.重力、支持力、静摩擦力均增大B.重力不变,支持力减小,静摩擦力不变C.重力不变,支持力、静摩擦力增大D.重力不变,支持力增大,静摩擦力减小3.物体在几个共点力作用下处于平衡状态,当其中的一个力撤掉后〔其它的力不变〕,物体的运动情况是A.一定做匀加速直线运动B.一定做匀变速曲线运动C.可能做匀速运动D.可能做曲线运动4.运动的升降机的顶板上有一个螺丝脱落到它的地板上,当升降机的运动分别处于加速上升、匀速上升、匀速下降和加速下降这四种情况下,螺丝从脱落到落到地板上的时间分别为t1、t2、t3和t4,比拟这四种情况下的落地时间,正确的表达式是A.t1<t2<t3<t4 B.t1<t2=t3<t4 C.t1=t2=t3=t4 D.t1>t2>t3>t4 5.如下列图,倾角为θ的斜面体C置于水平面上,B置于斜面上,通过细绳跨过光滑的定滑轮与A相连接,连接B的一段绳与斜面平行,C处于静止状态,B沿斜面匀速上滑,在A落地前,如下说法中正确的答案是A.B受到C的摩擦力一定不为零B.C受到水平面的摩擦力一定为零C.为论B、C间摩擦力大小、方向如何,水平面对C的摩擦力方向一定水平向左D.水平面对C的支持力与A、B、C的总重力大小相等6.一步行者以6.0m/s2的速度跑去追赶被红灯阻停的公共汽车,在跑到距离公共汽车25m 处时,绿灯亮了,汽车以1.0m/s2的加速度匀加速启动前进,如此A.人能追上公共汽车,追赶过程中人跑了36mB.人不能追上公共汽车,人、车最近距离是7mC.人能追上公共汽车,追上车前人共跑了43mD.人不能追上公共汽车,且车子开动后人和车相距越来越远7.如下列图,质量分别为m1=2kg,m2=3kg的两个物体置于光滑的水平面上,中间用一轻弹簧秤连接。
湖南师范大学附属中学2024届高三上学期月考(二)数学试题
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2014年 全国统一高考数学 试卷及解析(理科)(新课标ⅱ)
2014年全国统一高考数学试卷(理科)(新课标Ⅱ)一、选择题:本大题共12小题,每小题5分,在每小题给出的四个选项中,只有一个选项符合题目要求.1.(5分)设集合M={0,1,2},N={x|x2﹣3x+2≤0},则M∩N=()A.{1}B.{2}C.{0,1}D.{1,2}2.(5分)设复数z1,z2在复平面内的对应点关于虚轴对称,z1=2+i,则z1z2=()A.﹣5 B.5 C.﹣4+i D.﹣4﹣i3.(5分)设向量,满足|+|=,|﹣|=,则•=()A.1 B.2 C.3 D.54.(5分)钝角三角形ABC 的面积是,AB=1,BC=,则AC=()A.5 B .C.2 D.15.(5分)某地区空气质量监测资料表明,一天的空气质量为优良的概率是0.75,连续两天为优良的概率是0.6,已知某天的空气质量为优良,则随后一天的空气质量为优良的概率是()A.0.8 B.0.75 C.0.6 D.0.456.(5分)如图,网格纸上正方形小格的边长为1(表示1cm),图中粗线画出的是某零件的三视图,该零件由一个底面半径为3cm,高为6cm的圆柱体毛坯切削得到,则切削掉部分的体积与原来毛坯体积的比值为()1A .B .C .D .7.(5分)执行如图所示的程序框图,若输入的x,t均为2,则输出的S=()A.4 B.5 C.6 D.78.(5分)设曲线y=ax﹣ln(x+1)在点(0,0)处的切线方程为y=2x,则a=()2A.0 B.1 C.2 D.39.(5分)设x,y 满足约束条件,则z=2x﹣y的最大值为()A.10 B.8 C.3 D.210.(5分)设F为抛物线C:y2=3x的焦点,过F且倾斜角为30°的直线交C于A,B两点,O为坐标原点,则△OAB的面积为()A .B .C .D .11.(5分)直三棱柱ABC﹣A1B1C1中,∠BCA=90°,M,N分别是A1B1,A1C1的中点,BC=CA=CC1,则BM与AN所成角的余弦值为()A .B .C .D .12.(5分)设函数f(x)=sin,若存在f(x)的极值点x0满足x02+[f(x0)]2<m2,则m的取值范围是()A.(﹣∞,﹣6)∪(6,+∞)B.(﹣∞,﹣4)∪(4,+∞)C.(﹣∞,﹣2)∪(2,+∞)D.(﹣∞,﹣1)∪(1,+∞)二、填空题:本大题共4小题,每小题5分.(第13题~第21题为必考题,每个试题考生都必须作答,第22题~第24题为选考题,考生根据要求作答)13.(5分)(x+a)10的展开式中,x7的系数为15,则a=.14.(5分)函数f(x)=sin(x+2φ)﹣2sinφcos(x+φ)的最大值为.315.(5分)已知偶函数f(x)在[0,+∞)单调递减,f(2)=0,若f(x﹣1)>0,则x的取值范围是.16.(5分)设点M(x0,1),若在圆O:x2+y2=1上存在点N,使得∠OMN=45°,则x0的取值范围是.三、解答题:解答应写出文字说明,证明过程或验算步骤.17.(12分)已知数列{a n}满足a1=1,a n+1=3a n+1.(Ⅰ)证明{a n+}是等比数列,并求{a n}的通项公式;(Ⅱ)证明:++…+<.18.(12分)如图,四棱锥P﹣ABCD中,底面ABCD为矩形,PA⊥平面ABCD,E 为PD的中点.(Ⅰ)证明:PB∥平面AEC;(Ⅱ)设二面角D﹣AE﹣C为60°,AP=1,AD=,求三棱锥E﹣ACD的体积.19.(12分)某地区2007年至2013年农村居民家庭人均纯收入y(单位:千元)的数据如表:4年份2007200820092010201120122013年份代号t12345672.93.3 3.64.4 4.85.2 5.9人均纯收入y(Ⅰ)求y关于t的线性回归方程;(Ⅱ)利用(Ⅰ)中的回归方程,分析2007年至2013年该地区农村居民家庭人均纯收入的变化情况,并预测该地区2015年农村居民家庭人均纯收入.附:回归直线的斜率和截距的最小二乘估计公式分别为:=,=﹣.20.(12分)设F1,F2分别是C :+=1(a>b>0)的左,右焦点,M是C 上一点且MF2与x轴垂直,直线MF1与C的另一个交点为N.(1)若直线MN 的斜率为,求C的离心率;(2)若直线MN在y轴上的截距为2,且|MN|=5|F1N|,求a,b.21.(12分)已知函数f(x)=e x﹣e﹣x﹣2x.(Ⅰ)讨论f(x)的单调性;(Ⅱ)设g(x)=f(2x)﹣4bf(x),当x>0时,g(x)>0,求b的最大值;(Ⅲ)已知1.4142<<1.4143,估计ln2的近似值(精确到0.001).5请考生在第22、23、24三题中任选一题作答,如果多做,则按所做的第一题计分,作答时请写清题号.【选修4-1:几何证明选讲】22.(10分)如图,P是⊙O外一点,PA是切线,A为切点,割线PBC与⊙O相交于点B,C,PC=2PA,D为PC的中点,AD的延长线交⊙O于点E,证明:(Ⅰ)BE=EC;(Ⅱ)AD•DE=2PB2.【选修4-4:坐标系与参数方程】23.在直角坐标系xOy中,以坐标原点为极点,x轴正半轴为极轴建立极坐标系,半圆C的极坐标方程为ρ=2cosθ,θ∈[0,](Ⅰ)求C的参数方程;(Ⅱ)设点D在半圆C上,半圆C在D处的切线与直线l:y=x+2垂直,根据(1)中你得到的参数方程,求直线CD的倾斜角及D的坐标.六、解答题(共1小题,满分0分)624.设函数f(x)=|x +|+|x﹣a|(a>0).(Ⅰ)证明:f(x)≥2;(Ⅱ)若f(3)<5,求a的取值范围.72014年全国统一高考数学试卷(理科)(新课标Ⅱ)参考答案与试题解析一、选择题:本大题共12小题,每小题5分,在每小题给出的四个选项中,只有一个选项符合题目要求.1.(5分)设集合M={0,1,2},N={x|x2﹣3x+2≤0},则M∩N=()A.{1}B.{2}C.{0,1}D.{1,2}【分析】求出集合N的元素,利用集合的基本运算即可得到结论.【解答】解:∵N={x|x2﹣3x+2≤0}={x|(x﹣1)(x﹣2)≤0}={x|1≤x≤2},∴M∩N={1,2},故选:D.【点评】本题主要考查集合的基本运算,比较基础.2.(5分)设复数z1,z2在复平面内的对应点关于虚轴对称,z1=2+i,则z1z2=()A.﹣5 B.5 C.﹣4+i D.﹣4﹣i【分析】根据复数的几何意义求出z2,即可得到结论.【解答】解:z1=2+i对应的点的坐标为(2,1),8∵复数z1,z2在复平面内的对应点关于虚轴对称,∴(2,1)关于虚轴对称的点的坐标为(﹣2,1),则对应的复数,z2=﹣2+i,则z1z2=(2+i)(﹣2+i)=i2﹣4=﹣1﹣4=﹣5,故选:A.【点评】本题主要考查复数的基本运算,利用复数的几何意义是解决本题的关键,比较基础.3.(5分)设向量,满足|+|=,|﹣|=,则•=()A.1 B.2 C.3 D.5【分析】将等式进行平方,相加即可得到结论.【解答】解:∵|+|=,|﹣|=,∴分别平方得+2•+=10,﹣2•+=6,两式相减得4•=10﹣6=4,即•=1,故选:A.【点评】本题主要考查向量的基本运算,利用平方进行相加是解决本题的关键,比较基础.94.(5分)钝角三角形ABC 的面积是,AB=1,BC=,则AC=()A.5 B .C.2 D.1【分析】利用三角形面积公式列出关系式,将已知面积,AB,BC的值代入求出sinB的值,分两种情况考虑:当B为钝角时;当B为锐角时,利用同角三角函数间的基本关系求出cosB的值,利用余弦定理求出AC的值即可.【解答】解:∵钝角三角形ABC 的面积是,AB=c=1,BC=a=,∴S=acsinB=,即sinB=,当B为钝角时,cosB=﹣=﹣,利用余弦定理得:AC2=AB2+BC2﹣2AB•BC•cosB=1+2+2=5,即AC=,当B为锐角时,cosB==,利用余弦定理得:AC2=AB2+BC2﹣2AB•BC•cosB=1+2﹣2=1,即AC=1,此时AB2+AC2=BC2,即△ABC为直角三角形,不合题意,舍去,则AC=.故选:B.【点评】此题考查了余弦定理,三角形面积公式,以及同角三角函数间的基本关系,熟练掌握余弦定理是解本题的关键.105.(5分)某地区空气质量监测资料表明,一天的空气质量为优良的概率是0.75,连续两天为优良的概率是0.6,已知某天的空气质量为优良,则随后一天的空气质量为优良的概率是()A.0.8 B.0.75 C.0.6 D.0.45【分析】设随后一天的空气质量为优良的概率为p,则由题意可得0.75×p=0.6,由此解得p的值.【解答】解:设随后一天的空气质量为优良的概率为p,则由题意可得0.75×p=0.6,解得p=0.8,故选:A.【点评】本题主要考查相互独立事件的概率乘法公式的应用,属于基础题.6.(5分)如图,网格纸上正方形小格的边长为1(表示1cm),图中粗线画出的是某零件的三视图,该零件由一个底面半径为3cm,高为6cm的圆柱体毛坯切削得到,则切削掉部分的体积与原来毛坯体积的比值为()11A .B .C .D .【分析】由三视图判断几何体的形状,通过三视图的数据求解几何体的体积即可.【解答】解:几何体是由两个圆柱组成,一个是底面半径为3高为2,一个是底面半径为2,高为4,组合体体积是:32π•2+22π•4=34π.底面半径为3cm,高为6cm的圆柱体毛坯的体积为:32π×6=54π切削掉部分的体积与原来毛坯体积的比值为:=.故选:C.【点评】本题考查三视图与几何体的关系,几何体的体积的求法,考查空间想象能力以及计算能力.127.(5分)执行如图所示的程序框图,若输入的x,t均为2,则输出的S=()A.4 B.5 C.6 D.7【分析】根据条件,依次运行程序,即可得到结论.【解答】解:若x=t=2,则第一次循环,1≤2成立,则M=,S=2+3=5,k=2,第二次循环,2≤2成立,则M=,S=2+5=7,k=3,此时3≤2不成立,输出S=7,故选:D.【点评】本题主要考查程序框图的识别和判断,比较基础.138.(5分)设曲线y=ax﹣ln(x+1)在点(0,0)处的切线方程为y=2x,则a=()A.0 B.1 C.2 D.3【分析】根据导数的几何意义,即f′(x0)表示曲线f(x)在x=x0处的切线斜率,再代入计算.【解答】解:,∴y′(0)=a﹣1=2,∴a=3.故选:D.【点评】本题是基础题,考查的是导数的几何意义,这个知识点在高考中是经常考查的内容,一般只要求导正确,就能够求解该题.在高考中,导数作为一个非常好的研究工具,经常会被考查到,特别是用导数研究最值,证明不等式,研究零点问题等等经常以大题的形式出现,学生在复习时要引起重视.9.(5分)设x,y 满足约束条件,则z=2x﹣y的最大值为()A.10 B.8 C.3 D.2【分析】作出不等式组对应的平面区域,利用目标函数的几何意义,利用数形结合确定z的最大值.【解答】解:作出不等式组对应的平面区域如图:(阴影部分ABC).14由z=2x﹣y得y=2x﹣z,平移直线y=2x﹣z,由图象可知当直线y=2x﹣z经过点C时,直线y=2x﹣z的截距最小,此时z最大.由,解得,即C(5,2)代入目标函数z=2x﹣y,得z=2×5﹣2=8.故选:B.【点评】本题主要考查线性规划的应用,结合目标函数的几何意义,利用数形结合的数学思想是解决此类问题的基本方法.10.(5分)设F为抛物线C:y2=3x的焦点,过F且倾斜角为30°的直线交C于A,B两点,O为坐标原点,则△OAB的面积为()1516A .B .C .D .【分析】由抛物线方程求出焦点坐标,由直线的倾斜角求出斜率,写出过A ,B 两点的直线方程,和抛物线方程联立后化为关于y 的一元二次方程,由根与系数关系得到A ,B 两点纵坐标的和与积,把△OAB 的面积表示为两个小三角形AOF 与BOF 的面积和得答案.【解答】解:由y 2=2px ,得2p=3,p=,则F (,0).∴过A ,B 的直线方程为y=(x ﹣),即x=y +.联立 ,得4y 2﹣12y ﹣9=0.设A (x 1,y 1),B (x 2,y 2), 则y 1+y 2=3,y 1y 2=﹣.∴S △OAB =S △OAF +S △OFB =×|y 1﹣y 2|==×=.故选:D .【点评】本题考查直线与抛物线的位置关系,考查数学转化思想方法,涉及直线和圆锥曲线关系问题,常采用联立直线和圆锥曲线,然后利用一元二次方程的根与系数关系解题,是中档题.11.(5分)直三棱柱ABC﹣A1B1C1中,∠BCA=90°,M,N分别是A1B1,A1C1的中点,BC=CA=CC1,则BM与AN所成角的余弦值为()A .B .C .D .【分析】画出图形,找出BM与AN所成角的平面角,利用解三角形求出BM与AN所成角的余弦值.【解答】解:直三棱柱ABC﹣A1B1C1中,∠BCA=90°,M,N分别是A1B1,A1C1的中点,如图:BC 的中点为O,连结ON,,则MN0B是平行四边形,BM与AN所成角就是∠ANO,∵BC=CA=CC1,设BC=CA=CC1=2,∴CO=1,AO=,AN=,MB===,在△ANO中,由余弦定理可得:cos∠ANO===.故选:C.【点评】本题考查异面直线对称角的求法,作出异面直线所成角的平面角是解题17的关键,同时考查余弦定理的应用.12.(5分)设函数f(x)=sin,若存在f(x)的极值点x0满足x02+[f(x0)]2<m2,则m的取值范围是()A.(﹣∞,﹣6)∪(6,+∞)B.(﹣∞,﹣4)∪(4,+∞)C.(﹣∞,﹣2)∪(2,+∞)D.(﹣∞,﹣1)∪(1,+∞)【分析】由题意可得,f(x0)=±,且=kπ+,k∈Z,再由题意可得当m2最小时,|x0|最小,而|x0|最小为|m|,可得m2 >m2+3,由此求得m的取值范围.【解答】解:由题意可得,f(x0)=±,即=kπ+,k∈z,即x0=m.再由x02+[f(x0)]2<m2,即x02+3<m2,可得当m2最小时,|x0|最小,而|x0|最小为|m|,∴m2 >m2+3,∴m2>4.求得m>2,或m<﹣2,故选:C.【点评】本题主要正弦函数的图象和性质,函数的零点的定义,体现了转化的数学思想,属于中档题.18二、填空题:本大题共4小题,每小题5分.(第13题~第21题为必考题,每个试题考生都必须作答,第22题~第24题为选考题,考生根据要求作答)13.(5分)(x+a)10的展开式中,x7的系数为15,则a=.【分析】在二项展开式的通项公式中,令x的幂指数等于3,求出r的值,即可求得x7的系数,再根据x7的系数为15,求得a的值.【解答】解:(x +a)10的展开式的通项公式为T r=•x10﹣r•a r,+1令10﹣r=7,求得r=3,可得x7的系数为a3•=120a3=15,∴a=,故答案为:.【点评】本题主要考查二项式定理的应用,二项展开式的通项公式,求展开式中某项的系数,二项式系数的性质,属于中档题.14.(5分)函数f(x)=sin(x+2φ)﹣2sinφcos(x+φ)的最大值为1.【分析】由条件利用两角和差的正弦公式、余弦公式化简函数的解析式为f(x)=sinx,从而求得函数的最大值.【解答】解:函数f(x)=sin(x+2φ)﹣2sinφcos(x+φ)=sin[(x+φ)+φ]﹣2sinφcos (x+φ)=sin(x+φ)cosφ+cos(x+φ)sinφ﹣2sinφcos(x+φ)=sin(x+φ)cosφ﹣cos(x+φ)sinφ19=sin[(x+φ)﹣φ]=sinx,故函数f(x)的最大值为1,故答案为:1.【点评】本题主要考查两角和差的正弦公式、余弦公式的应用,正弦函数的最值,属于中档题.15.(5分)已知偶函数f(x)在[0,+∞)单调递减,f(2)=0,若f(x﹣1)>0,则x的取值范围是(﹣1,3).【分析】根据函数奇偶性和单调性之间的关系将不等式等价转化为f(|x﹣1|)>f(2),即可得到结论.【解答】解:∵偶函数f(x)在[0,+∞)单调递减,f(2)=0,∴不等式f(x﹣1)>0等价为f(x﹣1)>f(2),即f(|x﹣1|)>f(2),∴|x﹣1|<2,解得﹣1<x<3,故答案为:(﹣1,3)【点评】本题主要考查函数奇偶性和单调性之间的关系的应用,将不等式等价转化为f(|x﹣1|)>f(2)是解决本题的关键.2016.(5分)设点M(x0,1),若在圆O:x2+y2=1上存在点N,使得∠OMN=45°,则x0的取值范围是[﹣1,1] .【分析】根据直线和圆的位置关系,画出图形,利用数形结合即可得到结论.【解答】解:由题意画出图形如图:点M(x0,1),要使圆O:x2+y2=1上存在点N,使得∠OMN=45°,则∠OMN的最大值大于或等于45°时一定存在点N,使得∠OMN=45°,而当MN与圆相切时∠OMN取得最大值,此时MN=1,图中只有M′到M″之间的区域满足MN≤1,∴x0的取值范围是[﹣1,1].【点评】本题考查直线与圆的位置关系,直线与直线设出角的求法,数形结合是快速解得本题的策略之一.21三、解答题:解答应写出文字说明,证明过程或验算步骤.17.(12分)已知数列{a n}满足a1=1,a n+1=3a n+1.(Ⅰ)证明{a n +}是等比数列,并求{a n}的通项公式;(Ⅱ)证明:++…+<.【分析】(Ⅰ)根据等比数列的定义,后一项与前一项的比是常数,即=常数,又首项不为0,所以为等比数列;再根据等比数列的通项化式,求出{a n}的通项公式;(Ⅱ)将进行放大,即将分母缩小,使得构成一个等比数列,从而求和,证明不等式.【解答】证明(Ⅰ)==3,∵≠0,∴数列{a n +}是以首项为,公比为3的等比数列;∴a n +==,即;(Ⅱ)由(Ⅰ)知,22当n≥2时,∵3n﹣1>3n﹣3n﹣1,∴<=,∴当n=1时,成立,当n≥2时,++…+<1+…+==<.时,++…+<.∴对n∈N+【点评】本题考查的是等比数列,用放缩法证明不等式,证明数列为等比数列,只需要根据等比数列的定义就行;数列与不等式常结合在一起考,放缩法是常用的方法之一,通过放大或缩小,使原数列变成一个等比数列,或可以用裂项相消法求和的新数列.属于中档题.18.(12分)如图,四棱锥P﹣ABCD中,底面ABCD为矩形,PA⊥平面ABCD,E 为PD的中点.(Ⅰ)证明:PB∥平面AEC;(Ⅱ)设二面角D﹣AE﹣C为60°,AP=1,AD=,求三棱锥E﹣ACD的体积.23【分析】(Ⅰ)连接BD交AC于O点,连接EO,只要证明EO∥PB,即可证明PB ∥平面AEC;(Ⅱ)延长AE至M连结DM,使得AM⊥DM,说明∠CMD=60°,是二面角的平面角,求出CD,即可三棱锥E﹣ACD的体积.【解答】(Ⅰ)证明:连接BD交AC于O点,连接EO,∵O为BD中点,E为PD中点,∴EO∥PB,(2分)EO⊂平面AEC,PB⊄平面AEC,所以PB∥平面AEC;(6分)(Ⅱ)解:延长AE至M连结DM,使得AM⊥DM,∵四棱锥P﹣ABCD中,底面ABCD为矩形,PA⊥平面ABCD,∴CD⊥平面AMD,∴CD⊥MD.∵二面角D﹣AE﹣C为60°,∴∠CMD=60°,∵AP=1,AD=,∠ADP=30°,24∴PD=2,E为PD的中点.AE=1,∴DM=,CD==.三棱锥E﹣ACD 的体积为:==.【点评】本题考查直线与平面平行的判定,几何体的体积的求法,二面角等指数的应用,考查逻辑思维能力,是中档题.19.(12分)某地区2007年至2013年农村居民家庭人均纯收入y(单位:千元)的数据如表:25年份2007200820092010201120122013年份代号t12345672.93.3 3.64.4 4.85.2 5.9人均纯收入y(Ⅰ)求y关于t的线性回归方程;(Ⅱ)利用(Ⅰ)中的回归方程,分析2007年至2013年该地区农村居民家庭人均纯收入的变化情况,并预测该地区2015年农村居民家庭人均纯收入.附:回归直线的斜率和截距的最小二乘估计公式分别为:=,=﹣.【分析】(Ⅰ)根据所给的数据,利用最小二乘法可得横标和纵标的平均数,横标和纵标的积的和,与横标的平方和,代入公式求出b的值,再求出a的值,写出线性回归方程.(Ⅱ)根据上一问做出的线性回归方程,代入所给的t的值,预测该地区2015年农村居民家庭人均纯收入,这是一个估计值.【解答】解:(Ⅰ)由题意,=×(1+2+3+4+5+6+7)=4,=×(2.9+3.3+3.6+4.4+4.8+5.2+5.9)=4.3,∴==26=0.5,=﹣=4.3﹣0.5×4=2.3.∴y关于t 的线性回归方程为=0.5t+2.3;(Ⅱ)由(Ⅰ)知,b=0.5>0,故2007年至2013年该地区农村居民家庭人均纯收入逐年增加,平均每年增加0.5千元.将2015年的年份代号t=9代入=0.5t+2.3,得:=0.5×9+2.3=6.8,故预测该地区2015年农村居民家庭人均纯收入为6.8千元.【点评】本题考查线性回归分析的应用,本题解题的关键是利用最小二乘法认真做出线性回归方程的系数,这是整个题目做对的必备条件,本题是一个基础题.20.(12分)设F1,F2分别是C :+=1(a>b>0)的左,右焦点,M是C 上一点且MF2与x轴垂直,直线MF1与C的另一个交点为N.(1)若直线MN 的斜率为,求C的离心率;(2)若直线MN在y轴上的截距为2,且|MN|=5|F1N|,求a,b.【分析】(1)根据条件求出M的坐标,利用直线MN 的斜率为,建立关于a,27c的方程即可求C的离心率;(2)根据直线MN在y轴上的截距为2,以及|MN|=5|F1N|,建立方程组关系,求出N的坐标,代入椭圆方程即可得到结论.【解答】解:(1)∵M是C上一点且MF2与x轴垂直,∴M的横坐标为c,当x=c时,y=,即M(c ,),若直线MN 的斜率为,即tan∠MF1F2=,即b2==a2﹣c2,即c2+﹣a2=0,则,即2e2+3e﹣2=0解得e=或e=﹣2(舍去),即e=.(Ⅱ)由题意,原点O是F1F2的中点,则直线MF1与y轴的交点D(0,2)是线段MF1的中点,28设M(c,y),(y>0),则,即,解得y=,∵OD是△MF1F2的中位线,∴=4,即b2=4a,由|MN|=5|F1N|,则|MF1|=4|F1N|,解得|DF1|=2|F1N|,即设N(x1,y1),由题意知y1<0,则(﹣c,﹣2)=2(x1+c,y1).即,即代入椭圆方程得,将b2=4a 代入得,解得a=7,b=.29【点评】本题主要考查椭圆的性质,利用条件建立方程组,利用待定系数法是解决本题的关键,综合性较强,运算量较大,有一定的难度.21.(12分)已知函数f(x)=e x﹣e﹣x﹣2x.(Ⅰ)讨论f(x)的单调性;(Ⅱ)设g(x)=f(2x)﹣4bf(x),当x>0时,g(x)>0,求b的最大值;(Ⅲ)已知1.4142<<1.4143,估计ln2的近似值(精确到0.001).【分析】对第(Ⅰ)问,直接求导后,利用基本不等式可达到目的;对第(Ⅱ)问,先验证g(0)=0,只需说明g(x)在[0+∞)上为增函数即可,从而问题转化为“判断g′(x)>0是否成立”的问题;对第(Ⅲ)问,根据第(Ⅱ)问的结论,设法利用的近似值,并寻求ln2,于是在b=2及b>2的情况下分别计算,最后可估计ln2的近似值.【解答】解:(Ⅰ)由f(x)得f′(x)=e x+e﹣x﹣2,即f′(x)≥0,当且仅当e x=e﹣x即x=0时,f′(x)=0,∴函数f(x)在R上为增函数.30(Ⅱ)g(x)=f(2x)﹣4bf(x)=e2x﹣e﹣2x﹣4b(e x﹣e﹣x)+(8b﹣4)x,则g′(x)=2[e2x+e﹣2x﹣2b(e x+e﹣x)+(4b﹣2)]=2[(e x+e﹣x)2﹣2b(e x+e﹣x)+(4b﹣4)]=2(e x+e﹣x﹣2)(e x+e﹣x+2﹣2b).①∵e x+e﹣x>2,e x+e﹣x+2>4,∴当2b≤4,即b≤2时,g′(x)≥0,当且仅当x=0时取等号,从而g(x)在R上为增函数,而g(0)=0,∴x>0时,g(x)>0,符合题意.②当b>2时,若x满足2<e x+e﹣x<2b﹣2即,得,此时,g′(x)<0,又由g(0)=0知,当时,g(x)<0,不符合题意.综合①、②知,b≤2,得b的最大值为2.(Ⅲ)∵1.4142<<1.4143,根据(Ⅱ)中g(x)=e2x﹣e﹣2x﹣4b(e x﹣e﹣x)+(8b﹣4)x,为了凑配ln2,并利用的近似值,故将ln 即代入g(x)的解析式中,得.当b=2时,由g(x)>0,得,31从而;令,得>2,当时,由g(x)<0,得,得.所以ln2的近似值为0.693.【点评】1.本题三个小题的难度逐步增大,考查了学生对函数单调性深层次的把握能力,对思维的要求较高,属压轴题.2.从求解过程来看,对导函数解析式的合理变形至关重要,因为这直接影响到对导数符号的判断,是解决本题的一个重要突破口.3.本题的难点在于如何寻求ln2,关键是根据第(2)问中g(x)的解析式探究b的值,从而获得不等式,这样自然地将不等式放缩为的范围的端点值,达到了估值的目的.请考生在第22、23、24三题中任选一题作答,如果多做,则按所做的第一题计分,作答时请写清题号.【选修4-1:几何证明选讲】22.(10分)如图,P是⊙O外一点,PA是切线,A为切点,割线PBC与⊙O相交于点B,C,PC=2PA,D为PC的中点,AD的延长线交⊙O于点E,证明:(Ⅰ)BE=EC;(Ⅱ)AD•DE=2PB2.32【分析】(Ⅰ)连接OE,OA,证明OE⊥BC,可得E 是的中点,从而BE=EC;(Ⅱ)利用切割线定理证明PD=2PB,PB=BD,结合相交弦定理可得AD•DE=2PB2.【解答】证明:(Ⅰ)连接OE,OA,则∠OAE=∠OEA,∠OAP=90°,∵PC=2PA,D为PC的中点,∴PA=PD,∴∠PAD=∠PDA,∵∠PDA=∠CDE,∴∠OEA+∠CDE=∠OAE+∠PAD=90°,∴OE⊥BC,∴E 是的中点,∴BE=EC;(Ⅱ)∵PA是切线,A为切点,割线PBC与⊙O相交于点B,C,∴PA2=PB•PC,∵PC=2PA,33∴PA=2PB,∴PD=2PB,∴PB=BD,∴BD•DC=PB•2PB,∵AD•DE=BD•DC,∴AD•DE=2PB2.【点评】本题考查与圆有关的比例线段,考查切割线定理、相交弦定理,考查学生分析解决问题的能力,属于中档题.【选修4-4:坐标系与参数方程】23.在直角坐标系xOy中,以坐标原点为极点,x轴正半轴为极轴建立极坐标系,半圆C的极坐标方程为ρ=2cosθ,θ∈[0,](Ⅰ)求C的参数方程;(Ⅱ)设点D在半圆C上,半圆C在D处的切线与直线l:y=x+2垂直,根据(1)中你得到的参数方程,求直线CD的倾斜角及D的坐标.34【分析】(1)利用即可得出直角坐标方程,利用cos2t+sin2t=1进而得出参数方程.(2)利用半圆C在D处的切线与直线l:y=x+2垂直,则直线CD的斜率与直线l的斜率相等,即可得出直线CD的倾斜角及D的坐标.【解答】解:(1)由半圆C的极坐标方程为ρ=2cosθ,θ∈[0,],即ρ2=2ρcosθ,可得C的普通方程为(x﹣1)2+y2=1(0≤y≤1).可得C 的参数方程为(t为参数,0≤t≤π).(2)设D(1+cos t,sin t),由(1)知C是以C(1,0)为圆心,1为半径的上半圆,∵直线CD的斜率与直线l的斜率相等,∴tant=,t=.故D 的直角坐标为,即(,).【点评】本题考查了把极坐标方程化为直角坐标方程、参数方程化为普通方程、直线与圆的位置关系,考查了推理能力与计算能力,属于中档题.六、解答题(共1小题,满分0分)24.设函数f(x)=|x +|+|x﹣a|(a>0).(Ⅰ)证明:f(x)≥2;(Ⅱ)若f(3)<5,求a的取值范围.35【分析】(Ⅰ)由a>0,f(x)=|x +|+|x﹣a|,利用绝对值三角不等式、基本不等式证得f(x)≥2成立.(Ⅱ)由f(3)=|3+|+|3﹣a|<5,分当a>3时和当0<a≤3时两种情况,分别去掉绝对值,求得不等式的解集,再取并集,即得所求.【解答】解:(Ⅰ)证明:∵a>0,f(x)=|x +|+|x﹣a|≥|(x +)﹣(x﹣a)|=|a +|=a +≥2=2,故不等式f(x)≥2成立.(Ⅱ)∵f(3)=|3+|+|3﹣a|<5,∴当a>3时,不等式即a +<5,即a2﹣5a+1<0,解得3<a <.当0<a≤3时,不等式即6﹣a +<5,即a2﹣a﹣1>0,求得<a≤3.综上可得,a 的取值范围(,).【点评】本题主要考查绝对值三角不等式,绝对值不等式的解法,体现了转化、分类讨论的数学思想,属于中档题.36。
2014年高考数学真题汇编(含答案):数列
2014年全国高考理科数学试题分类汇编(纯word 解析版) 十一、数列(逐题详解)第I 部分1.【2014年重庆卷(理02)】对任意等比数列{}n a ,下列说法一定正确的是( )139.,,A a a a 成等比数列 236.,,B a a a 成等比数列 248.,,C a a a 成等比数列 369.,,D a a a 成等比数列【答案】D【解析】设{}n a 公比为q ,因为336936,a aq q a a ==,所以369,,a a a 成等比数列,选择D2.【2014年福建卷(理03)】等差数列{a n }的前n 项和为S n ,若a 1=2,S 3=12,则a 6等于( ) A .8 B .10 C .12 D .14【答案】C【解析】由题意可得S 3=a 1+a 2+a 3=3a 2=12,解得a 2=4,∴公差d=a 2﹣a 1=4﹣2=2,∴a 6=a 1+5d=2+5×2=12,故选:C .3.【2014年辽宁卷(理08)】设等差数列{}n a 的公差为d ,若数列1{2}n a a为递减数列,则( )A .0d <B .0d >C .10a d <D .10a d >【答案】C【解析】∵等差数列{a n }的公差为d ,∴a n+1﹣a n =d ,又数列{2}为递减数列,∴=<1,∴a 1d <0.故选:C4.【2014年全国大纲卷(10)】等比数列{}n a 中,452,5a a ==,则数列{lg }n a 的前8项和等于( )A .6B .5C .4D .3【答案】C【解析】∵等比数列{a n }中a 4=2,a 5=5,∴a 4•a 5=2×5=10,∴数列{lga n }的前8项和S=lga 1+lga 2+…+lga 8=lg (a 1•a 2…a 8)=lg (a 4•a 5)4=4lg (a 4•a 5)=4lg10=4故选:C第II 部分5.【2014年上海卷(理08)】设无穷等比数列{}n a 的公比为q ,若()134lim n n a a a a →∞=+++,则q = .【答案】q =【解析】:22311110112a a q a q q q q q -±==⇒+-=⇒=--,∵01q <<,∴q =6.【2014年广东卷(理13)】若等比数列{}n a 的各项均为正数,且512911102e a a a a =+,则1220ln ln ln a a a +++= 。
湖南师大附中2014届高三第七次月考文综试题
湖南师大附中2014届高三第七次月考文综试题时量:1 5 0分满分:300分本试卷分第1卷(选择题)和第Ⅱ卷《菲选择题)两部分。
1至4 1题是必考题,42至48题为选考题。
第I卷选择题(共1 4 0分)本卷共3 5 小题,每小题4分j共1 40分。
在每小题列出的四个选项中多只有一项是符合题目要求的。
日本《产经新闻》20 1 3年5月4日报道:东北大学地质学副教授小宫刚等人在加拿大东北地区发现了距今3 9。
6亿年前形成的沉积岩。
这比之前公认最古老的沉积岩还要早1。
3亿年,将成为研究生命诞生之初的原始地理环境的重要材料。
小宫等人自2 0 1 1年至今在加拿大最东北的拉布拉多地区进行调查,对裸露在地表的铁矿石进行了取样。
通过对内部夹杂的花岗岩进行年代测定,小宫等人判定这是最古老的沉积岩。
可以认为,这是原本沉积在海底的矿物等变硬形成的。
据此回答1~3题。
1.根据材料,联系相关知识,下列推测合理的是A.该处沉积岩一直在地表B.该处沉积岩为花岗岩C.该沉积岩是世界上最古老的岩石D.该沉积岩可能含有地表生物的信息2.沉积岩是研究地理原始环境重要材料的原因是A.外力作用形成B.位于地壳表面C.有化石D.在岩石圈中体积最大3.关于加拿大拉布拉多地区的地理特征,叙述正确的是A.以山地为主B.为温带季风气候C.位于板块交界处,地壳运动活跃D.三面临海,岩石古老读我国局部区域图,回答4~6题。
4.关于图示区域的说法,错误的是A.以丘陵、平原为主B.属于湿润、半湿润地区C.主要属于黄河流域D.②③城市均临黄海5.③处比①处冬季气温高,关系不大的因素是A.地形阻挡B.距海近C.D.6.将①处钢铁厂迁往③处,主要原因是A.降低运输成本B.③处钢材需求量大C.减轻①处环境污染.D.③处铁矿丰富九江石化总厂是江西省唯一一家集炼油、化肥、化工为一体的大型石化企业,原油主要自山东胜利油田及海外进口,其炼油厂生产的汽油、柴油主要供应江西省内,厂址选择充分考虑了生态效益和经济效益。
2023届湖南省湖南师范大学附属中学高三下学期月考物理试题(七)试题含答案
湖南师大附中2023届高三月考试卷(七)物理注意事项:1.答卷前,考生务必将自己的姓名,准考证号填写在答题卡上。
2.回答选择题时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑。
如需改动,用橡皮擦干净后,再选涂其他答案标号。
回答非选择题时,将答案写在答题卡上。
写在本试卷上无效。
3.考试结束后,将本试题卷和答题卡一并交回。
第I 卷一、单项选择题(本题共6小题,每小题4分,共24分。
每小题给出的四个选项中,只有一个选项是符合题目要求的)1.下列叙述中符合物理学史的有()A.汤姆孙通过研究阴极射线实验,发现了电子和质子的存在B.普朗克为了解释黑体辐射现象,第一次提出了能量量子化理论C.法拉第发现了电磁感应现象,并得出了法拉第电磁感应定律D.玻尔提出的原子模型,彻底否定了卢瑟福的原子核式结构学说2.a 、b 两车在平直公路上行驶,a 车以2v 0的初速度做匀减速运动,b 车做初速度为零的匀加速运动。
在t =0时,两车间距为0且a 车在b 车后方。
在t =t 1时两车速度相同,均为v 0,且在0~t 1时间内,a 车的位移大小为s 。
下列说法正确的是()A.0~t 1时间内a 、b 两车相向而行B.0~t 1时间内a 车平均速度大小是b 车平均速度大小的2倍C.若a 、b 在t 1时刻相遇,则s 0=23s D.若a 、b 在12t 时刻相遇,则下次相遇时刻为2t 13.如图,斜面体放置在水平地面上,粗糙的小物块放在斜面上。
甲图中给小物块施加一个沿斜面向上的力1F ,使它沿斜面向上匀速运动;乙图中给小物块施加一水平向右的力2F ,小物块静止在斜面上。
甲、乙图中斜面体始终保持静止。
下列判断正确的是()A.1F 增大,斜面对小物块的摩擦力一定增大B.1F 增大,地面对斜面体的摩擦力不变C.2F 增大,斜面对物块的摩擦力一定增大D.2F 增大,物块最终一定能沿斜面向上滑动4.如图所示,某电动工具置于水平地面上。
湖南师大附中2014届高三第七次月考历史试题 Word版含答案
湖南师大附中2014届高三第七次月考历史试题(word版)时量:1 5 0分满分:300分本试卷分第1卷(选择题)和第Ⅱ卷《菲选择题)两部分。
1至4 1题是必考题,42至48题为选考题。
第I卷选择题(共1 4 0分)本卷共3 5 小题,每小题4分j共1 40分。
在每小题列出的四个选项中多只有一项是符合题目要求的。
24.“国权不下县.,县下唯宗族,宗族皆自治,自治靠伦理,伦理造乡绅”是某学者总结出的关于中国古代传统乡村的认识范式。
对这种范式理解正确的是A.国家一宗族二元模式强化了中央集权B.宗法制成为维护等级制的有力工具C.郡县制有利于儒家伦理道德贯彻渗透D.乡绅自治有利于维护乡村社会秩序25.清代著名学者赵翼在《廿二史札记》中提出:“西汉开国,功臣多出于亡命无赖,至光武中兴,则诸将帅皆有儒者气象,亦一时风会不同也。
"这种现象出现的主要原因是A.汉初“无为而治"政策影响B.汉代儒学成为正统的影响C.科举制提高了官员的文化素质D.宋代理学思想渗透的结果26.明朝小说《金瓶梅》的故事于《水浒传》,但主人公却由侠士武松变为商人西门庆,《三言》《二拍》中的许多故事采自唐宋传奇,但主人公却由仕宦之子、将门之后变成了商人。
这反映出A.社会动荡导致传统价值观的缺失B.世俗文学成为反封建的主要载体C.商人社会地位发生了明显的改变D.重农抑商政策发生了根本性改变27.右图是根据邓洪波等《中国书院制度研究》统计的《清代书院分布图》,该图反映出A.清代文化重心与经济中心基本一致B.南北文化发展呈现相对均衡的趋势C.西南地区成为全国教育和学术中心D.清代对思想文化的控制越越严密28.太平天国后期流传着“天父杀天兄,江山打有通;空手转回家,仍旧做田工。
天父杀天兄空;蛟龙非金龙,仍旧喊咸丰。
"的歌谣。
对其理解准确的是A.天京事变是太平天国运动失败的根B.《天朝田亩制度》从未真正实行过,C.太平天国政权从未得到民众真正认可D.反映了太平天国政权信仰理论的缺陷2 9.1 8世纪的欧洲,一股前所未有的“法语热"风靡除了英国之外的几乎整个欧洲。
湖南师大附中2014届高三英语第七次月考试题牛津译林版
湖南师大附中2014届高三第七次月考英语试题PartⅠ Listening Comprehension (30 marks)Section A(22.5 marks)Directions In this section, you will hear six conversations between two speakers.For each conversation, there are several questions and each question is followed by three choices marked A, B and C.Listen carefully and then choose the best answer for each question.You will hear each conversation TWICE.Conversation 1l.What does the boy want to do?A.Watch a movie.B.Go to an amusement park.C.Watch a TV program.2.According to the boy, what will his father think of his idea?A.He will definitely agree with it.B.He won’t want to spend the money.C.He will say it’s too noisy.Conversation 23.Where does the conversation take place?A.At the airport.B.At a travel agency.C.In a supermarket.4.What will the woman do next?A.Buy some bottled water.B.Go through the security check.C.Drink up her water.Conversation 35.Where was the woman when the accident happened?A.On an overhead bridge.B.In a car.C.In a truck.6.What probably caused the accidentA.The car driver being drunk.B.The car going too fast.C.Something wrong with the.truck..Conversation 47.Why does the man make the phone call?A.He wants to.book for the show.B.He wants to get some information about the show.C.He wants to know on what day the show will be given.8.How much does the tickets cost if the wants to buy one?A.30 dollars.B.13 dollarsC.33 dollars9.When will the show probably end?A.At 10;00 p.m.B.At 8;00 p.m.C.At about midnight.Conversation 510.What is the woman planning to do?A.Watch the game on television.B.Attend the game.C.Find someone to sing with.11.What does the man think when the woman says she is not going?A.She has no money left.B.She doesn’t like football.C.She isn’t feeling well.12.What does the man miss when watching a game on television?A.Photographing the sports ground.B.Watching the ball.C.Peopled excitement.Conversation13.Who is Rogers most probably?A.Tom’s friend.B.Tom’s teacher.C.Tom’s boss.14.What did Tom tell his mother in yesterday^ letter?A.He, had decided to work part-timeB.He had lost his new job.C.He had just bought a car15.Why does Tom tell his mother about his job?A.He doesn’t want her to worry about his job.B.He doesn’t want her to worry about his life.C.He doesn’t want her to worry about his studies.Section B (7.5 marks)Directions In this section, you will hear a short passage.Listen carefully and then fill in the numbered blanks with the information you have heard.Fill in each blank with NO MORE THAN THREE WORDS.You will hear the short passage TWICE.Part II Language Knowledge (45 marks)Section A (15 marks)Directions For each of the following unfinished sentences there are four choices marked A, B, C and D.Choose the one that best completes the sentence.21.Some scientific evidence suggests musical training before the age of seven _____ have a significant impact on the brain's development.A.should B.canC.must D.need22.What the separatists did on Mar.1st in Kunming was extremely violent, _____ will only add to the importance the country attaches to the unity of all ethnic groups.A.when B.why C.what D.which 23.LiNa beat Dominika Cibulkova at the Australian Open to storm to her second grand slam title, _____another huge boost to Asian tennis.A.giving B.having givenC.gave D.to give24.At the end of World War Q those people who had participated in that conflict believed that if they were victorious over the Nazis, they _____ celebrated and honored by their nation.A.would be B.will have been C.will be D.would have been25.—Have you watched the movie Gravity—Yes, I_____it with my sister.A.have watched B.watchedC.have been watching D.watch26.He had never expected ______ a woman calling herself his mother on his 20th birthday.A.there being B.there isC.there have been D.there to be27.Chinese researchers announced they had successfully developed the vaccine for the H7N9 bird flu virus, after the flu vim’s had left more than 130 people _____, with 45 deaths reported.A.to infect B.infectedC.having infected D.infecting .28, I do hope.that the road sign I have placed at the crossroads will be- helpful to _____ feels confused or gets lost there.A.no matter whom B.no matter whoC.whomever D.whoever29.You must tell Mr, Wang about the incident _____ you meet him.A.quickly B.quietlyC.while D.immediately30._____ he misunderstood my position on the problem was obvious from his comments.A.Which B.Where C That D.What 31.—Oh, where is my wallet? Maybe I left it in the car.—You_____ something.A.were always leaving B.have always leftC.always leave D.are always leaving32.Under no circumstances in the last one year _____ for leave because of personal affairs.A.did she ask B.she askedC.has she asked D.she has asked33.Everyone thinks James _____ the money from Ann’s drawer, since he is alway s honest.A.shouldn’t have taken B.couldn't takeC.mustn’t have taken D.couldn’t have taken34.So far many possible means have been tried, but none _____ to be practical.A.was proved B.have been provedC.proves D.proved.35.The cost of organic food is higher than _____ of conventional food because the organic price tag reflects more closely the true cost of growing the food.A.it B.one C.that D.this Section B(18 marks)Directions; For each blank in the following passage there are four words or phrases marked A, B, C and D.Fill in each blank with the word or phrase that best fits the context.The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer used in business field.In the past 15 years, pilots have reported over 100 36 that could have teen caused by electromagnetic interference (电磁场干扰).The source of this interference remains _37_, but increasingly, experts are pointing the 38 at portable electronic devices such as computers, radios, cassette players and mobile telephones.RTCA, Radio Technical Commission for Aeronautics, has recommended that 39 airlines should ban such electronic devic es from being used during some "critical‖ stages of flight, 40 when the plane is taking off and landing.Some experts have gone further, 41 a total ban during all stages of flights.42 some airlines forbid-passengers from using such devices during taking off and landing, most don't want to enforce a total ban because many passengers want to work during flights.The 43 is predicting how electromagnetic fields might affect an aircraft's computers.Experts know that portable devices release radiation, which 44 those waves that aircraft use for navigation and communication.But they have not been able to produce these effects in a lab, so they have no way of knowing whether the interference might be 45 or not.The fact that aircrafts may be easy to be attacked by interference 46 alarm bells ringing terrorists may use radio system in order to 47 navigation equipment.36.A.actions B.events C.matters D.incidents 37.A.unfinished B.uncheckedC.unconfirmed D.unmentioned38.A.error B.blameC.pressure D.burden39.A.some B.severalC.all D.no40.A.especially B.obviously C.unfortunately D.possibly 41.A.looking for B.calling for C.waiting for D.searching for 42.A.If B.When C.As D.Though 43.A.idea B.difficulty C.possibility D.necessity 44.A.aims B.advises C.affects D.aids 45.A.useful B.dangerous C.useless D.necessary 46.A.faces B.sets C.makes D.takes 47.A.repair B.guide C.lead D.damage Section C (12 marks)Directions Complete the following passage by filling in.each blank with one word that best fits the context.You can’t understand the pain of overweight people 48.you have been one.I used to be an overweight boy, weighing 95kg in junior high.I was often laughed at by others, 49.cast a big shadow on my heart- I was afraid of wearing T-shirts and shorts.Even in the hottest summer, I 50.went swimming with-my friends because I was ashamed of my fat figure.I became less and less confident, afraid of talking in public and always hiding 51.I told myself many times that I must lose weight but I didn't have 52.courage to take action.53., as I suffered from obesity more and more, I finally decided to go on a diet and do a lot of exercise.The miracle came two months 54.I had reduced my weight to 70kg! When my friends saw me, they didn't even recognize men’s handsome boy 55.with a strong figure! I'm thankful for this experience, from which I really learned a truth nothing can stop me if I really want to achieve my dream.Part III Reading Comprehension(30 marks.)Directions Read the following three passages.Each passage is followed by several questions or unfinished statements.For each of them there are four choices marked A,B,C and D.Choose the one that fits best according to the information given in the passage.Zach Marks wasn't supposed to be able to get on an adult social-networking website.After all, he was an 11-year-old boy from Melbourne Beach, Florida-younger than the limited age.To his joy, hundreds of people made friends with him, including grown-ups he didn't know.He saw images he probably shouldn't have seen.Unfortunately he got caught by his father.By all accounts, Zach's dad was not happy."We had a really heated argument," Zach said."And in the middle of the argument, I told my dad that there was no safe social-networking site out there for kids." That's when inspiration struck.Today, at the age of 12, Zach is the creative force behind Grom Social a, new social-networking site that is created by kids and for kids.Zach came up with an idea himself and created it with the help from his family.Grom Social is safe, fun and educational.Only kids are allowed on Grom Social.And in order for them to get on, they have to enter their parents' e-mailaddresses.In that way, the parents can monitor everything their kids say and do while on the site."There are people looking at it 24 hours a day, seven days a week," Zach said."You can't say anything bad.You can't post any inappropriate pictures." There are also cool contents and positive messages specifically for kids."A grom is a young and upcoming athlete, gamer, surfer," Zach said."It's a promising young individual that's quick to learn." By early March, Grom Social's membership was 20,000 worldwide and growing.And Zach and his family have partnered with an IT firm in New York City that has invested several million dollars in the site."It's amazing how this is all happening and taking off," Zach's dad said."Today, everyone Zach chats with on the site wants to know if he is real or not.Please keep in mind that he is only a 12-year-old kid."56.What did Zach learn from his experience on a social-networking website?A.Social-networking websites were not safe for kids.B.He was so young that he couldn't surf the Internet.C.Adults were more willing to make friends with kids.D.He could get more useful information from the website.57.After arguing with his dad , Zach .A.encouraged his dad to surf the Internet with himB.persuaded his dad to help him create Grom SocialC.decided to create a new social-networking website for kidsD.began to realize the key role the kids are playing online58.According to the passage, what do we know about Grom Social?A.It was created by Zach on his own.B.It must be visited by kids with their parents.C.It doesn’t welcom e any cool contents.D.It is looked at by some people continuously.59.What Zach’s dad said in Paragraph 7 suggested that.A.Zach’s dad is proud of what Zach has achievedB.Zach has become successful only within one yearC.Zach is determined to spend more money on the siteD.most people don’t think highly of what Zach has done60.Which of the following can be the best title for the passage?A.A great plan made by a young kidB.Kid gets a good idea from a websiteC.An unusual kid and his contributionD.Kid creates a kids-only social networkBBelow are the top four supermarket chains in the world in 2012 and the reasons behind their success.TescoHeadquartered in Chestnut, United Kingdom , this global grocery store is one of the largest supermarket chains in terms of revenues and profits. If was founded in 1919 by Jack Cohen. Tesco stores can be found across all continents. Even though it was set up only for food and beverages, Tesco has drastically branched out , not only in geographical terms, but also in terms of products.Which now include electronics , clothing, health care, home improvement and even financial services.SafewayFounded in the year 1915 by a young M. B, Skaggs. Safeway developed from just a small grocery store on the fundamentals of providing value to customers and narrow profit margins. The success story of Skaggs becomes more evident when , by the end of the year 1926,he he had opened almost 428 stores across ten states. Almost two years later, Safeway was listed at the New York Stock Exchange . At present, there are more than fifteen hundred Safeway stores across US and Canada.The Kroger CompanyFounded at Cincinnati, Ohio in 1883 by Mr. Bernard Kroger, the Kroger Company is now one of the largest supermarket chains not only in the US. but across the world . Over the last couple of decades, the Kroger Company has vastly expanded by acquiring popular brand names, including those of Owen’s Market. Its stores are largely spread out across Middle. Western and Central United States.Reve-GruppeReve – Gruppe was founded in 1927 and is presently headquartered at Cologne, Germany . This supermarket chain is easily counted among the top supermarket chains of the world . Its vast ine of products includes grocery, home improvement, pharmaceuticals, cosmetics, optical as well as clothing . Its stores can be found in as many as fourteen European countries, providing employment to more than 325,000 people.61.Which of the following was founded first ?A.Tesco. B.Safeway.C.The Kroger Company. D.Rewe-Gruppe.62.We can learn from the text that Safeway .A.was initially set up only for foodB.developed from a small grocery storeC.has about 3,500 stores nowD.has branches in fourteen European countries63.Which of the following is TRUE?A.Tesco was founded four years earlier than Safeway.B.Tesco and Safeway are headquartered in the same country.C.Rewe - Gruppe provides financial services.D.Safeway was listed at the New York Stock Exchange around 1928.64.According to the passage, the Kroger Company .A.is presently headquartered in the United KingdomB.has fifteen stores in the US and CanadaC.developed quickly after acquiring popular brand namesD.provides employment for more than 325,000 people65.What is the topic of the passage?A.An introduction to four top supermarket chains around the world.B.The history of four top supermarkets chains.C.The background of four supermarket chains.D.The most profitable supermarket chains in the world.CPicture a wasteland of old computer monitors and TVs, stretching as far as the eye can see. Imagine towers of boxes, all of them filled with broken glass and discarded electronic devices. Technology graveyards like this can be found in communities across the country.Experts say that landfills and warehouses will overflow unless a plan for the disposal (清理)and reuse of electronics is put into place .‖ We can’t put electronics and glass aside and tell ourselves we’ll deal with them later , ‖Laure n Roman , managing director of Transparent Planet said. Roman’s group works to improve the disposal of electronic waste. She says about 660 million pounds of tech trash is produced each year in the U.S.What’s behind the tech trash pile-up ?About ten years ago ,major advances were made in computer and television technology . Manufacturers began producing devices like flat –paneled LCDs and plasma(等离子) screen monitors. These new products provide a clearer image and take up less space than older models. It goes without saying that consumers choose them rather than heavy. Glass-based technologies.The new electronics are built with materials that are difficult to recycle. In addition, the new products have decreased the demand for recycled parts from the older monitors and screens. Older, heavier computer monitors and TVs used glass-based components called CRTs.CRTs have a high lead content and can be environmentally hazardous if not recycled properly . If crushed and put in landfills, the lead from CUTs could seep into groundwater and rivers, harming the water supply. For many years, plants and recycling programs safely processed CRTs. The recycled CRTs were reused in the construction of new monitors.Monitors being made today do not use glass tubes . ―Peo ple are returning old –style TVs with CRTs , but no new ones are being made ,‖ said Linnell. This is creating an imbalance in the amount of glass being disposed of and recycled properly. Many recycling companies have shut down. Others no longer have the resources or space to process these materials. This results in stockpiling.However , experts say there are ways to safely and responsibly address the tech-trash problem.66.What is the main idea of the passage?A.New technology causes trouble for recyclers.B.Experts are trying to solve the tech-trash problem.C.New technology has both advantages and disadvantages.D.CRTs from old computer monitors and TVs harm the earth.67.What Lauren Roman says in Paragraph 2 shows that .A.people attach great importance to electronic wasteB.he has found a new way on how to dispose electronic wasteC.figuring out how to deal with electronic waste is urgent\D.more landfills are needed for storing electronics and glass68.We learn from Paragraph 3 that flat-paneled plasmas and LEDs .A.produce wastes which are less harmfulB.are using heavy , grass-based technologies.C.are very easy for recyclers to recycle for reuseD.are putting heavy, glass-based technologies out lf the market69.W hat does the underlined word ―hazardous‖ in Paragraph 5 most probably mean?A.Risky.B.Helpless.C.Extreme.D.Unnecessary.70.What would the writer probably talk about next?A.Some other problems related to technologies.B.Some experts’ opinions on the tech-trash problem.C.Some reasons why the tech-trash problem is hard to solve.D.Some practicable ways to solve the tech-trash problem.Part Ⅳ Writing(45 marks)Section A (10 marks)Directions Read the following passage.Fill in the numbered blanks by using the information from the passage.Write NO MORE THAN THREE WORDS for each answer.Nowadays graduates often face strong competition in the search for jobs.Three stages are often highlighted for them to follow in the process of finding a career recognizing abilities, matching these to jobs available and presenting them well to possible employers.Job seekers have to make a careful assessment of their abilities. One area of assessment should be of their academic qualifications, which include special skills within their subject area. Graduates should also consider their own values and attitudes. An honest assessment of personal interests and abilities such as creative skills, or skills acquired from work experience, should also be given careful thoughtThe second stage is to study the opportunities which are available for employment. To do this, graduates can study job and position information in newspapers, or they can pay a visit to a careers office, write to friends or relatives who may already be involved in a particular profession. After studying all the various options, they should be in a position to make informed comparisons between various careers.Good personal presentation is essential in the search for a good career. Job application forms should be filled in carefully and correctly, without grammar of spelling errors. They should also prepare properly by finding out all they can about the possible employer. When additional information b asked for, job seekers should describe their abilities and work experience in more depth, as well as balance their own abilities with the employer's needs, explain why they are interested in a career with the particular company and try to show that they already know something about the company and its activities. For an interview, they should dress suitably and arrive on time. Interviewees should try to give positive answers and not be afraid of asking questions about anything they are unsure about.If the graduates have ability and are determined, they will be lucky enough to follow an ideal career.Section B (10 marks)Directions Read the following passage. Answer the questions according to the information given in the passage .Not all memories are sweet. Some people spend all their lives trying to forget bad experiences. Violence and traffic accidents can leave people with terrible physical and emotional scars. Often these experiences appear over and over again in nightmares,Now American researchers think they are close to developing a pill. which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce, or possibly erase, the effect of painful memories.In November. experts tested a drug on people in the US and France. The drug stops the body releasing chemicals that fix memories in the brain. So far the research has suggested that only the emotional effects of memories may be reduced, not that the memories are erased.The research has caused a great deal of argument. Some think it is a bad idea. Those who are against the research say that changing memories is very dangerous. It is known that memories give us our identity and also help us avoid the mistakes of the past. "All of us can think of bad events in our lives that were horrible at the time but make us who we are. I'm not sure we'd want to wipe those memories out," said Rebecca Dresser, a medical ethicist. .Some people also fear that the drug would be abused although the drug should be used only in very serious cases. "People always have the ability to misuse science." said Joseph LeDoux, a New York University memory researcher." All we want to do is help people have better control of memories.However. there are still some supporters. who believe it could lead to pills that prevent or treat soldiers' troubling memories after war. In addition, they say that nowadays there are many people who suffer from terrible memories. "Some memories can ruin people's lives. They comeback to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions. "said Roger Pitman, a professor of psychiatry at Harvard Medical School. "This could relieve a lot of that suffering. "81. According to the passage, what experiences often bring people bad memories? (No more than 4 words)82. How does the drug work to reduce the emotional effects of memories? (No more than 12words) (2 marks)83. Why do some people think the research is a bad idea? (No more than 12 words) (3 marks)84. What's the main idea of the last paragraph? (No more than 8 words) (3 marks)Section C(25 marks)Directions Write an English composition according to the instructions given below.下面的这幅画展现了两人合作一张凳子却各忙各的情景,请根据对这幅画的理解,用英语写一篇短文。
湖南师大附中2005--2006学年度高三年级月考试题数学(理)
湖 南 师 大 附 中2005—2006学年度高三年级月考试题数学(理科)说明:本卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分.考试时间120分钟,满分150分.第Ⅰ卷(选择题 共50分)一、选择题:本大题共10小题,每小题5分,共50分,在每小题给出的四个选项中有且只有一项是符合题目要求的.1.若复数i a a a a z )2()2(22--+-=的纯虚数,则( )A .12≠≠a a 或B .12≠≠a a 且C .a =0D .a =2或a =0 2.若|)|1)(1(,x x R x -+∈那么是正数的充要条件是( )A .1||<xB .1<xC .1||>xD .111<<--<x x 或3.设全集I=R ,.}0)(|{},0)(|{R Q P x g x Q x f x P ≠≠≠⊂⊂⊂>=<=φ且满足则集合}0)(0)(|{≤≥=x g x f x M 且等于( )A .C I PB .C I QC .φD .(C I P )∪(C I Q )4.已知随机变量p n D E p n B 与则且,4.2,12),,(~==ξξξ的值分别是 ( )A .15与0.8B .16与0.8C .20与0.4D .12与0.65.在等差数列{a n }中,若a 2+ a 6+ a 16为一个确定的常数,则下列各个和中也为确定的常数的是 ( ) A .S 8 B .S 10 C .S 15 D .S 176.已知实数),(,2|1|)3()1(,22y x P y x y x y x 则点满足条件++=-+-的运动轨迹是( )A .抛物线B .双曲线C .椭圆D .圆7.已知f (x )是奇函数,且当x >0时,)(,0),1()(x f x x x x f 时那么当<+=的解析式是( )A .)1(x x --B .)1(x x -C .)1(x x +-D .)1(x x +8.设函数f (x )是可导函数,并且='=∆-∆-→∆)(,2)()2(lim0000x f xx f x x f x 则( )A .21B .-2C .0D .-19.设函数)12(),()(1-==-x f y x f x f y 现将函数的反函数为的图象向左平移2个单位,再关于x 轴对称后,所对应的函数的反函数是( )A .2)(31x f y --=B .2)(31x f y ---=C .2)(31x f y -+-=D .2)(31x f y -+=10.给出下列4个命题: ①若sin2A=sin2B ,则△ABC 是等腰三角形; ②若sinA=cosB ,则△ABC 是直角三角形; ③若cosAcosBcosC<0,则△ABC 是钝角三角形;④若cos(A -B)cos(B -C)cos(C -A)=1,则△ABC 是等边三角形.其中正确的命题是( )A .①③B .③④C .①④D .②③第Ⅱ卷(非选择题 共100分)二、填空题:本大题共5小题,每小题4分,共20分. 11.函数21)|lg(|xx x y --=的定义域为 .12.已知,)1(x e f x =+则函数)(x f 的解析式是)(x f = . 13.已知函数=-+-++≠>+=)41()21()41()21(),10(11)(f f f f a a a x f x 则且 .14.设向量||3||),sin ,(cos ),sin ,(cos a b y y b x x a =+==若,则=-)c o s (y x .15.求值:= 2222 .三、解答题:本大题共6小题,共80分.解答应写出文字说明、证明过程或演算步骤. 16.(12分)已知βα,为锐角,且试求,02sin 22sin 3,1sin 2sin 322=-=+βαβα)23c o s (βαπ++的值.17.(12分)已知双曲线2112222+>=-e by a x 的离心率,左、右焦点分别为F 1、F 2,左准线为l ,试推断在双曲线上的左支上是否存在点P ,使得|PF 1|是点P 到l 的距离d 与|PF 2|的等比中项?若存在,请求出点P 的坐标;若不存在,请说明理由.18.(14分)一袋中装有大小相同的8个小球,其中5个红球,3个黑球,现从中随机摸出3个球.(Ⅰ)求至少摸到一个红球的概率;(Ⅱ)求摸到黑球个数ξ的概率分布和数学期望.19.(14分)在三棱锥P —ABC 中,底面△ABC 是以B 为直角顶点的等腰直角三角形,点P 在底面ABC 上的射影H 在线段AC 上且靠近C 点,AC=4,14 PA ,PB 和底面所成角为45°.(Ⅰ)求点P 到底面ABC 的距离. (Ⅱ)求二面角P —AB —C 的正切值.20.(14分)已知函数))1(,1()(,)(23f P x f y c bx ax x x f 上的点过曲线=+++=的切线方程为y=3x +1.(Ⅰ)若函数2)(-=x x f 在处有极值,求)(x f 的表达式; (Ⅱ)在(Ⅰ)的条件下,求函数)(x f y =在[-3,1]上的最大值; (Ⅲ)若函数)(x f y =在区间[-2,1]上单调递增,求实数b 的取值范围.21.(14分)已知数列{a n }满足:*).(02,2,81241N n a a a a a n n n ∈=+-==++且 (Ⅰ)求数列{a n }的通项公式;(Ⅱ)求和2221224232221n n a a a a a a -++-+-- ;(Ⅲ)设n n n n b b b T N n a n b +++=∈-=21*),()12(1,若存在整数m ,使对任意n∈N*,均有32mT n >成立,求m 的最大值.高三数学(文)参考答案一、选择题:1.C2.D3.B4.A5.C6.A7.B8.D9.C 10.B 二、填空题11.(-1,0) 12.)1ln(-x 13.2 14.823 15.2 三、解答题:16.解:由⎩⎨⎧==βαβα2sin 22sin 32cos sin 32∵.02sin ,02sin ,2,20,2,0≠≠∴<<∴<<βαπβαπβα①÷② .2c o t t a nβα= 即 .2cot )2cot(βαπ=- …………6分 又∵220παπ<-<,∴.0)2cot(2cot >-=απβ∴22,22,220πβαβαππβ=+∴=-∴<<. …………10分∴.23)32cos()23cos(-=+=++ππβαπ…………12分 17.设在左支上存在P 点使|PF 1|2=|PF 2|·d ,则,||||||121PF PF d PF = ① ②又||||,||121PF e PF e dPF =∴= ① …………4分 又|PF 2|-|PF 1|=2a ②由①、②得.12||,12||21-=-=e aePF e a PF …………8分 因在△PF 1F 2中有 |PF 1|+|PF 2|≥2c ,∴c e aee a 21212≥-+- ③ …………10分 利用,ace =代入③得.2121,0122+≤≤-∴≤--e e e212111+>+≤<∴>e e e 与 矛盾.∴符合条件的点P 不存在. …………12分18.(1)至少摸到一个红球的概率 56551383505=-=C C C P …………4分 (2)ξ表示摸到黑球个数,则2815)1(;285)0(382513383503======C C C P C C C P ξξ; …………6分 561)3(;5615)2(38535381523======C C C P C C C P ξξ. …………8分 ∴摸到黑球个数ξ的概率分布为:∴E ξ=.8…………14分19.(1)∵P 在底面ABC 上的射影H 在线段AC 上,过P 作PH ⊥底面ABC ,则H 在AC上且靠近C 点,∴面PAC ⊥面ABC …………2分 在等腰Rt △ABC 中,连结BH 取AC 中点O ,连BO. 设PH=h ,由已知∠PBH=45°,则BH=h.…………4分在△OHB 中BO ⊥AC ,OB=222,221-==h OH AC 在Rt △PAH 中,PA 2=HA 2+PH 2. ∴5,14)24(222=∴=+-+h h h∴P 到底面ABC 之距离为5 ………7分(2)在H h OH h ∴=-==,12,522时是CO 中点.……9分在△ABC 中,过点H 作HM ⊥AB 于垂足为M ,连PM.则∠PMH 为二面角P —AB —C …………12分 ∵.3102235tan ,223224343==∠∴=⋅==PMH BC HM …………14分 20.(1)由.23)(,)(223b ax x x f c bx ax x x f ++='+++=求导数得过))1(,1()(f P x f y 上点=的切线方程为:).1)(23()1(),1)(1()1(-++=+++--'=-x b a c b a y x f f y 即 …………2分而过.13)]1(,1[)(+==x y f P x f y 的切线方程为上 故⎩⎨⎧-=-=+⎩⎨⎧-=-=++3023323c a b a c a b a 即 ∵124,0)2(,2)(-=+-∴=-'-==b a f x x f y 故时有极值在 ③由①②③得 a =2,b=-4,c=5.∴.542)(23+-+=x x x x f ………………5分(2)).2)(23(443)(2+-=-+='x x x x x f 当;0)(,322;0)(,23<'<≤->'-<≤-x f x x f x 时当时 13)2()(.0)(,132=-=∴>'≤<f x f x f x 极大时当 …………8分 又)(,4)1(x f f ∴=在[-3,1]上最大值是13. …………9分(3)y=f (x )在[-2,1]上单调递增,又,23)(2b ax x x f ++='由①知2a +b=0. 依题意)(x f '在[-2,1]上恒有)(x f '≥0,即.032≥+-b bx x ……10分 ① ②①当6,03)1()(,16min ≥∴>+-='='≥=b b b f x f b x 时; ②当φ∈∴≥++=-'='-≤=b b b f x f b x ,0212)2()(,26min 时; ③当.60,01212)(,1622min ≤≤≥-='≤≤-b b b x f b 则时 …………13分 综上所述,参数b 的取值范围是),0[+∞ …………14分21.(1)∵n n n n n n n a a a a a a a -=-=-=+++++1121202即∴数列{a n }成等差数列. ………………2分 由n a a a d a a n 210,232,81441-=∴-=-===得公差 ……4分 (2)2221224232221n n a a a a a a -++-+--)())(())(())((212432121221243432121n n n n n n a a a a a a d a a a a a a a a a a a a ++++++-=-++++-++-=--- ).29(42)(2221n n a a n n -=+⋅= …………9分 (3)∵).111(21)1(21)12(1+-=+=-=n n n n a n b n n …………10分 ∴n n b b b T +++= 21]1113121211[21+-++-+-=n n =.)1(2)111(21+=+-n n n …………11分 ∴0)1)(2(21)111(21)211(211>++=+--+-=-+n n n n T T n n ∴{T n }是递增数列. ∴411=T 是T n 的最小值. …………13分由83241<⇒>m m ∴满足条件的最大整数m=7 …………14分。
湖南师大附中2014届高三第七次月考英语试题
湖南师大附中2014届高三第七次月考英语试题本试卷分为四个部分,包括听力、语言知识运用、阅读和书面表达。
时量120分钟。
满分150分。
PartⅠ Listening Comprehension (30 marks)Section A(22.5 marks)Directions In this section, you will hear six conversations between two speakers.For each conversation, there are several questions and each question is followed by three choices marked A, B and C.Listen carefully and then choose the best answer for each question.You will hear each conversation TWICE.Conversation 1l.What does the boy want to do?A.Watch a movie.B.Go to an amusement park.C.Watch a TV program.2.According to the boy, what will his father think of his idea?A.He will definitely agree with it.B.He won’t want to spend the money.C.He will say it’s too noisy.Conversation 23.Where does the conversation take place?A.At the airport.B.At a travel agency.C.In a supermarket.4.What will the woman do next?A.Buy some bottled water.B.Go through the security check.C.Drink up her water.Conversation 35.Where was the woman when the accident happened?A.On an overhead bridge.B.In a car.C.In a truck.6.What probably caused the accidentA.The car driver being drunk.B.The car going too fast.C.Something wrong with the.truck..Conversation 47.Why does the man make the phone call?A.He wants to.book for the show.B.He wants to get some information about the show.C.He wants to know on what day the show will be given.8.How much does the tickets cost if the wants to buy one?A.30 dollars.B.13 dollarsC.33 dollars9.When will the show probably end?A.At 10;00 p.m.B.At 8;00 p.m.C.At about midnight.Conversation 510.What is the woman planning to do?A.Watch the game on television.B.Attend the game.C.Find someone to sing with.11.What does the man think when the woman says she is not going?A.She has no money left.B.She doesn’t like football.C.She isn’t feeling well.12.What does the man miss when watching a game on television?A.Photographing the sports ground.B.Watching the ball.C.Peopled excitement.Conversation13.Who is Rogers most probably?A.Tom’s friend.B.Tom’s teacher.C.Tom’s boss.14.What did Tom tell his mother in yesterday^ letter?A.He, had decided to work part-timeB.He had lost his new job.C.He had just bought a car15.Why does Tom tell his mother about his job?A.He doesn’t want her to worry about his job.B.He doesn’t want her to worry about his life.C.He doesn’t want her to worry about his studies.Section B (7.5 marks)Directions In this section, you will hear a short passage.Listen carefully and then fill in the numbered blanks with the information you have heard.Fill in each blank with NO MORE THAN THREE WORDS.You will hear the short passage TWICE.Part II Language Knowledge (45 marks)Section A (15 marks)Directions For each of the following unfinished sentences there are four choices marked A, B, C and D.Choose the one that best completes the sentence.21.Some scientific evidence suggests musical training before the age of seven _____ have a significant impact on the brain's development.A.should B.canC.must D.need22.What the separatists did on Mar.1st in Kunming was extremely violent, _____ will only add to the importance the country attaches to the unity of all ethnic groups.A.when B.why C.what D.which23.LiNa beat Dominika Cibulkova at the Australian Open to storm to her second grand slam title, _____another huge boost to Asian tennis.A.giving B.having givenC.gave D.to give24.At the end of World War Q those people who had participated in that conflict believed that if they were victorious over the Nazis, they _____ celebrated and honored by their nation.A.would be B.will have beenC.will be D.would have been25.—Have you watched the movie Gravity—Yes, I_____it with my sister.A.have watched B.watchedC.have been watching D.watch26.He had never expected ______ a woman calling herself his mother on his 20th birthday.A.there being B.there isC.there have been D.there to be27.Chinese researchers announced they had successfully developed the vaccine for the H7N9 bird flu virus, after the flu vim’s had left more than 130 peo ple _____, with 45 deaths reported.A.to infect B.infectedC.having infected D.infecting .28, I do hope.that the road sign I have placed at the crossroads will be- helpful to _____ feels confused or gets lost there.A.no matter whom B.no matter whoC.whomever D.whoever29.You must tell Mr, Wang about the incident _____ you meet him.A.quickly B.quietlyC.while D.immediately30._____ he misunderstood my position on the problem was obvious from his comments.A.Which B.Where C That D.What31.—Oh, where is my wallet? Maybe I left it in the car.—You_____ something.A.were always leaving B.have always leftC.always leave D.are always leaving32.Under no circumstances in the last one year _____ for leave because of personal affairs.A.did she ask B.she askedC.has she asked D.she has asked33.Everyone thinks James _____ the money from Ann’s drawer, since he is always honest.A.shouldn’t have taken B.couldn't takeC.mustn’t have taken D.couldn’t have taken34.So far many possible means have been tried, but none _____ to be practical.A.was proved B.have been provedC.proves D.proved.35.The cost of organic food is higher than _____ of conventional food because the organic price tag reflects more closely the true cost of growing the food.A.it B.one C.that D.thisSection B(18 marks)Directions; For each blank in the following passage there are four words or phrases marked A, B, C and D.Fill in each blank with the word or phrase that best fits the context.The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer used in business field.In the past 15 years, pilots have reported over 100 36 that could have teen caused by electromagnetic interference (电磁场干扰).The source of this interference remains _37_, but increasingly, experts are pointing the 38 at portable electronic devices such as computers, radios, cassette players and mobile telephones.RTCA, Radio Technical Commission for Aeronautics, has recommended that 39 airlines should ban such electronic devices from being used during some "critical”stages of flight, 40 when the plane is taking off and landing.Some experts have gone further, 41 a total ban during all stages of flights.42 some airlines forbid-passengers from using such devices during taking off and landing, most don't want to enforce a total ban because many passengers want to work during flights.The 43 is predicting how electromagnetic fields might affect an aircraft's computers.Experts know that portable devices release radiation, which 44 those waves that aircraft use for navigation and communication.But they have not been able to produce these effects in a lab, so they have no way of knowing whether the interference might be 45 or not.The fact that aircrafts may be easy to be attacked by interference 46 alarm bells ringing terrorists mayuse radio system in order to 47 navigation equipment.36.A.actions B.events C.matters D.incidents 37.A.unfinished B.uncheckedC.unconfirmed D.unmentioned38.A.error B.blameC.pressure D.burden39.A.some B.severalC.all D.no40.A.especially B.obviously C.unfortunately D.possibly 41.A.looking for B.calling for C.waiting for D.searching for 42.A.If B.When C.As D.Though43.A.idea B.difficulty C.possibility D.necessity 44.A.aims B.advises C.affects D.aids45.A.useful B.dangerous C.useless D.necessary 46.A.faces B.sets C.makes D.takes47.A.repair B.guide C.lead D.damage Section C (12 marks)Directions Complete the following passage by filling in.each blank with one word that best fits the context.You can’t understand the pain of overweight people 48.you have been one.I used to be an overweight boy, weighing 95kg in junior high.I was often laughed at by others, 49.cast a big shadow on my heart- I was afraid of wearing T-shirts and shorts.Even in the hottest summer, I 50.went swimming with-my friends because I was ashamed of my fat figure.I became less and less confident, afraid of talking in public and always hiding 51.I told myself many times that I must lose weight but I didn't have 52.courage to take action.53., as I suffered from obesity more and more, I finally decided to go on a diet and do a lot of exercise.The miracle came two months 54.I had reduced my weight to 70kg! When my friends saw me, they didn't even recognize me n’s handsome boy 55.with a strong figure! I'm thankful for this experience, from which I really learned a truth nothing can stop me if I really want to achieve my dream.Part III Reading Comprehension(30 marks.)Directions Read the following three passages.Each passage is followed by several questions or unfinished statements.For each of them there are four choices marked A,B,C and D.Choose the one that fits best according to the information given in the passage.Zach Marks wasn't supposed to be able to get on an adult social-networking website.After all, he was an 11-year-old boy from Melbourne Beach, Florida-younger than the limited age.To his joy, hundreds of people made friends with him, including grown-ups he didn't know.He saw images he probably shouldn't have seen.Unfortunately he got caught by his father.By all accounts, Zach's dad was not happy."We had a really heated argument," Zach said."And in the middle of the argument, I told my dad that there was no safe social-networking site out there for kids." That's when inspiration struck.Today, at the age of 12, Zach is the creative force behind Grom Social a, new social-networking site that is created by kids and for kids.Zach came up with an idea himself and created it with the help from hisfamily.Grom Social is safe, fun and educational.Only kids are allowed on Grom Social.And in order for them to get on, they have to enter their parents' e-mail addresses.In that way, the parents can monitor everything their kids say and do while on the site."There are people looking at it 24 hours a day, seven days a week," Zach said."You can't say anything bad.You can't post any inappropriate pictures." There are also cool contents and positive messages specifically for kids."A grom is a young and upcoming athlete, gamer, surfer," Zach said."It's a promising young individual that's quick to learn." By early March, Grom Social's membership was 20,000 worldwide and growing.And Zach and his family have partnered with an IT firm in New York City that has invested several million dollars in the site."It's amazing how this is all happening and taking off," Zach's dad said."Today, everyone Zach chats with on the site wants to know if he is real or not.Please keep in mind that he is only a 12-year-old kid." 56.What did Zach learn from his experience on a social-networking website?A.Social-networking websites were not safe for kids.B.He was so young that he couldn't surf the Internet.C.Adults were more willing to make friends with kids.D.He could get more useful information from the website.57.After arguing with his dad , Zach .A.encouraged his dad to surf the Internet with himB.persuaded his dad to help him create Grom SocialC.decided to create a new social-networking website for kidsD.began to realize the key role the kids are playing online58.According to the passage, what do we know about Grom Social?A.It was created by Zach on his own.B.It must be visited by kids with their parents.C.It doesn’t welcome any cool contents.D.It is looked at by some people continuously.59.What Zach’s dad said in Paragraph 7 suggested that .A.Zach’s dad is proud of what Zach has achievedB.Zach has become successful only within one yearC.Zach is determined to spend more money on the siteD.most people don’t think highly of what Zach has done60.Which of the following can be the best title for the passage?A.A great plan made by a young kidB.Kid gets a good idea from a websiteC.An unusual kid and his contributionD.Kid creates a kids-only social networkBBelow are the top four supermarket chains in the world in 2012 and the reasons behind their success.TescoHeadquartered in Chestnut, United Kingdom , this global grocery store is one of the largest supermarket chains in terms of revenues and profits. If was founded in 1919 by Jack Cohen. Tesco storescan be found across all continents. Even though it was set up only for food and beverages, Tesco has drastically branched out , not only in geographical terms, but also in terms of products. Which now include electronics , clothing, health care, home improvement and even financial services.SafewayFounded in the year 1915 by a young M. B, Skaggs. Safeway developed from just a small grocery store on the fundamentals of providing value to customers and narrow profit margins. The success story of Skaggs becomes more evident when , by the end of the year 1926,he he had opened almost 428 stores across ten states. Almost two years later, Safeway was listed at the New York Stock Exchange . At present, there are more than fifteen hundred Safeway stores across US and Canada.The Kroger CompanyFounded at Cincinnati, Ohio in 1883 by Mr. Bernard Kroger, the Kroger Company is now one of the largest supermarket chains not only in the US. but across the world . Over the last couple of decades, the Kroger Company has vastly expanded by acquiring popular brand names, including those of Owen’s Market. Its stores are largely spread out across Middle. Western and Central United States.Reve-GruppeReve –Gruppe was founded in 1927 and is presently headquartered at Cologne, Germany . This supermarket chain is easily counted among the top supermarket chains of the world . Its vast ine of products includes grocery, home improvement, pharmaceuticals, cosmetics, optical as well as clothing . Its stores can be found in as many as fourteen European countries, providing employment to more than 325,000 people. 61.Which of the following was founded first ?A.Tesco. B.Safeway.C.The Kroger Company. D.Rewe-Gruppe.62.We can learn from the text that Safeway .A.was initially set up only for foodB.developed from a small grocery storeC.has about 3,500 stores nowD.has branches in fourteen European countries63.Which of the following is TRUE?A.Tesco was founded four years earlier than Safeway.B.Tesco and Safeway are headquartered in the same country.C.Rewe - Gruppe provides financial services.D.Safeway was listed at the New York Stock Exchange around 1928.64.According to the passage, the Kroger Company .A.is presently headquartered in the United KingdomB.has fifteen stores in the US and CanadaC.developed quickly after acquiring popular brand namesD.provides employment for more than 325,000 people65.What is the topic of the passage?A.An introduction to four top supermarket chains around the world.B.The history of four top supermarkets chains.C.The background of four supermarket chains.D.The most profitable supermarket chains in the world.CPicture a wasteland of old computer monitors and TVs, stretching as far as the eye can see. Imagine towers of boxes, all of them filled with broken glass and discarded electronic devices. Technology graveyards like this can be found in communities across the country.Experts say that landfills and warehouses will overflow unless a plan for the disposal (清理)and reuse of electronics is put into place .” We can’t put electronics and glass aside and tell ourselves we’ll deal with them later , ”Lauren Roman , managing director of Transparent Planet said. Roman’s group works to improve the disposal of electronic waste. She says about 660 million pounds of tech trash is produced each year in the U.S.What’s behind the tech trash pile-up ?About ten years ago ,major advances were made in computer and television technology . Manufacturers began producing devices like flat –paneled LCDs and plasma(等离子) screen monitors. These new products provide a clearer image and take up less space than older models. It goes without saying that consumers choose them rather than heavy. Glass-based technologies.The new electronics are built with materials that are difficult to recycle. In addition, the new products have decreased the demand for recycled parts from the older monitors and screens. Older, heavier computer monitors and TVs used glass-based components called CRTs.CRTs have a high lead content and can be environmentally hazardous if not recycled properly . If crushed and put in landfills, the lead from CUTs could seep into groundwater and rivers, harming the water supply. For many years, plants and recycling programs safely processed CRTs. The recycled CRTs were reused in the construction of new monitors.Monitors being made today do not use glass tubes . “People are returning old –style TVs with CRTs , but no new ones are being made ,” said Linnell. This is creating an imbalance in the amount of glass being disposed of and recycled properly. Many recycling companies have shut down. Others no longer have the resources or space to process these materials. This results in stockpiling.However , experts say there are ways to safely and responsibly address the tech-trash problem. 66.What is the main idea of the passage?A.New technology causes trouble for recyclers.B.Experts are trying to solve the tech-trash problem.C.New technology has both advantages and disadvantages.D.CRTs from old computer monitors and TVs harm the earth.67.What Lauren Roman says in Paragraph 2 shows that .A.people attach great importance to electronic wasteB.he has found a new way on how to dispose electronic wasteC.figuring out how to deal with electronic waste is urgent\D.more landfills are needed for storing electronics and glass68.We learn from Paragraph 3 that flat-paneled plasmas and LEDs .A.produce wastes which are less harmfulB.are using heavy , grass-based technologies.C.are very easy for recyclers to recycle for reuseD.are putting heavy, glass-based technologies out lf the market69.What does the underlined word “hazardous” in Paragraph 5 most probably mean?A.Risky.B.Helpless.C.Extreme.D.Unnecessary.70.What would the writer probably talk about next?A.Some other problems related to technologies.B.Some experts’ opinions on the tech-trash problem.C.Some reasons why the tech-trash problem is hard to solve.D.Some practicable ways to solve the tech-trash problem.Part Ⅳ Writing(45 marks)Section A (10 marks)Directions Read the following passage.Fill in the numbered blanks by using the information from the passage.Write NO MORE THAN THREE WORDS for each answer.Nowadays graduates often face strong competition in the search for jobs.Three stages are often highlighted for them to follow in the process of finding a career recognizing abilities, matching these to jobs available and presenting them well to possible employers.Job seekers have to make a careful assessment of their abilities. One area of assessment should be of their academic qualifications, which include special skills within their subject area. Graduates should also consider their own values and attitudes. An honest assessment of personal interests and abilities such as creative skills, or skills acquired from work experience, should also be given careful thought The second stage is to study the opportunities which are available for employment. To do this, graduates can study job and position information in newspapers, or they can pay a visit to a careers office, write to friends or relatives who may already be involved in a particular profession. After studying all the various options, they should be in a position to make informed comparisons between various careers.Good personal presentation is essential in the search for a good career. Job application forms should be filled in carefully and correctly, without grammar of spelling errors. They should also prepare properly by finding out all they can about the possible employer. When additional information b asked for, job seekers should describe their abilities and work experience in more depth, as well as balance their own abilities with the employer's needs, explain why they are interested in a career with the particular company and try to show that they already know something about the company and its activities. For an interview, they should dress suitably and arrive on time. Interviewees should try to give positive answers and not be afraid of asking questions about anything they are unsure about.If the graduates have ability and are determined, they will be lucky enough to follow an ideal career.Section B (10 marks)Directions Read the following passage. Answer the questions according to the information given in the passage .Not all memories are sweet. Some people spend all their lives trying to forget bad experiences. Violence and traffic accidents can leave people with terrible physical and emotional scars. Often these experiences appear over and over again in nightmares,Now American researchers think they are close to developing a pill. which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce, or possibly erase, the effect of painful memories.In November. experts tested a drug on people in the US and France. The drug stops the body releasing chemicals that fix memories in the brain. So far the research has suggested that only the emotional effects of memories may be reduced, not that the memories are erased.The research has caused a great deal of argument. Some think it is a bad idea. Those who are against the research say that changing memories is very dangerous. It is known that memories give us our identity and also help us avoid the mistakes of the past. "All of us can think of bad events in our lives that were horrible at the time but make us who we are. I'm not sure we'd want to wipe those memories out," said Rebecca Dresser, a medical ethicist. .Some people also fear that the drug would be abused although the drug should be used only in very serious cases. "People always have the ability to misuse science." said Joseph LeDoux, a New York University memory researcher." All we want to do is help people have better control of memories.However. there are still some supporters. who believe it could lead to pills that prevent or treat soldiers' troubling memories after war. In addition, they say that nowadays there are many people whosuffer from terrible memories. "Some memories can ruin people's lives. They come back to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions. "said Roger Pitman, a professor of psychiatry at Harvard Medical School. "This could relieve a lot of that suffering. "81. According to the passage, what experiences often bring people bad memories? (No more than 4 words)82. How does the drug work to reduce the emotional effects of memories? (No more than 12 words) (2marks)83. Why do some people think the research is a bad idea? (No more than 12 words) (3 marks)84. What's the main idea of the last paragraph? (No more than 8 words) (3 marks)Section C(25 marks)Directions Write an English composition according to the instructions given below.下面的这幅画展现了两人合作一张凳子却各忙各的情景,请根据对这幅画的理解,用英语写一篇短文。
湖南师大附中2021-2022学年高三下学期月考数学试卷(七)
湖南师大附中2022届高三月考试卷(七)数学注意事项:1.答卷前,考生务必将自己的姓名、考生号、考场号、座位号填写在答题卡上.2.回答选择题时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑.如需改动,用橡皮擦干净后,再选涂其他答案标号,回答非选择题时,将答案写在答题卡上,写在本试卷上无效.3.考试结束后,将本试卷和答题卡一并交回.一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.设全集U={-3,-2,-1,0,1,2,3},集合A={-1,0,1,2},B={-3,2,3},则A (ðU B )=(А.{-1,0})B .{0,1}C .{-1,1}D .{-1,0,1}2.已知sin⎛33πα+⎫⎭⎪= ⎝,则sin ⎛2α+6π⎫⎭⎪的值为( ⎝)A .79B .-79C.9D .-93.某种活性细胞的存活率y (%)与存放温度x (℃)之间具有线性相关关系,样本数据如下表所示:存放温度x (℃)104-2-8存活率y (%)20445680经计算,回归直线的斜率为-3.2.若这种活性细胞的存放温度为6℃,则其存活率的预报值为(A .32%)B .33%C .34%D .35%4.已知双曲线C :x 2y 2=1(k >0),若对任意实数m ,直线4x +3y +m =0与C 至16k -多有一个交点,则C 的离心率为()A .45B .53C .43D .95.已知函数f (x )=⎨⎪⎛⎪f (x -1),x >21⎫,x ≤2⎝2x⎧ ⎭⎪⎩,则f (log 212)=()A .31B .-6C .61D .-36.中国古代数学瑰宝《九章算术》中记载了一种称为“曲池”的几何体,该几何体为上、下底面均为扇环形的柱体(扇环是指圆环被扇形截得的部分).现有一个如图所示的曲池,其中AA 1⊥底面ABCD ,底面扇环所对的圆心角为2π,A D 的长度为B C 的长度的3倍,AA 1=3,CD=2,则该曲池的体积为()C .A .9π2B .6π11π2D .5π第6题图7.考察下列两个问题:①已知随机变量X~B (第9题图n ,p ),且E (X )=4,D (X )=2,记P (X=1)=a ;②甲、乙、丙三人随机到某3个景点去旅游,每人只去一个景点,设A 表示“甲、乙、丙所去的景点互不相同”,B 表示“有一个景点仅甲一人去旅游”,记P (A|B )=b ,则()A .a =b 3B .a =b 4C .a =b 5D .a =b 68.在△ABC 中,角B ,C 的对边长分别为b ,c ,点O 为△ABC 的外心,若b 2+c 2=2b , 则BC ⋅AO 的取值范围是()A .⎡1,0⎫⎭⎪4-⎢⎣B .(0,2)C .⎡1,+∞⎫⎭⎪4-⎢⎣D .⎡1,2⎫⎭⎪4-⎢⎣二、选择题:本题共4小题,每小题5分,共20分.在每小题给出的选项中,有多项符合题目要求.全部选对的得5分,部分选对的得2分,有选错的得0分.9.如图所示,用一个与圆柱底面成θ(0<θ<2)角的平面截圆柱,截面是一个椭圆.若)π圆柱的底面圆半径为2,θ=A .椭圆的长轴长等于4,则(3πB .椭圆的离心率为32C .椭圆的标准方程可以是x 2y 2=1164+D .椭圆上的点到一个焦点的距离的最小值为4-10.已知f (x )是定义在R 上的偶函数,且对任意x ∈R ,有f (1+x )=-f (1-x ),当x ∈[0,1]时,f (x )=x 2+x -2,则(A .f (x )是以4为周期的周期函数B .f (2021)+f (2022)=-2)C .函数y =f (x )-log 2(x +1)有3个零点D .当x ∈[3,4]时,f (x )=x 2-9x +1811.已知函数f (x )=A sin (ωx +ϕ)(A >0,ω>0,-π<ϕ<-2)的部分图象如图π所示,把函数f (x )图象上所有点的横坐标伸长为原来的1110倍,得到函数y =g (x )的图象,则()A .g ⎛3x +π⎫⎭⎪为偶函数 ⎝B .g (x )的最小正周期是πC .g (x )的图象关于直线x =23π对称D .g (x )在区间(71π2,π)上单调递减第11题图第12题图12.如图,棱长为2的正方体ABCD −A 1B 1C 1D 1的内切球球心为O ,E 、F 分别是棱AB 、CC 1的中点,G 在棱BC 上移动,则(A .对于任意点G ,OA ∥平面EFGB .存在点G ,使OD ⊥平面EFGC .直线EF 的被球O)D .过直线EF 的平面截球O 所得截面圆面积的最小值为2π三、填空题:本题共4小题,每小题5分,共20分.13.已知复数z 满足z (1-i )=4+2i ,则z =________(用代数式表示).14.《数术记遗》是《算经十书》中的一部,相传是汉末徐岳所著.该书记述了我国古代14种算法,分别是:积算(即筹算)、太乙算、两仪算、三才算、五行算、八卦算、九宫算、运筹算、了知算、成数算、把头算、龟算、珠算和计数.某中学研究性学习小组有甲、乙、丙、丁四人,该小组拟全部收集九宫算、运筹算、了知算、成数算和把头算等5种算法的相关资料,要求每人至少收集其中一种,且每种算法只由一个人收集,但甲不收集九宫算和了知算的资料,则不同的分工收集方案共有________种.15.已知直线l过点P(0,1),且与圆O:x2+y2=3相交于A,B两点,设OC=OA+OB,若点C在圆O上,则直线l的倾斜角为________.16.已知函数f(x)=x-ae x+2.(1)若对任意实数x,f(x)<0恒成立,则a的取值范围是________;(2)若存在实数x1,x2(x1≠x2),使得f(x1)=f(x2)=0,则a的取值范围是________.四、解答题:本题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.(本小题满分10分)在△ABC中,已知sin2A-sin2B=sin C(sin B+sin C).(1)求角A的值;(2)设∠BAC的平分线交BC边于D,若AD=1,BC=,求△ABC的面积.在数列{a n}中,已知a1=2,n(a n+1-a n)=a n+1.(1)求数列{a n}的通项公式;S n(2)设b n=(-1)n a n,S n为数列{b n}的前n项和,求满足>100的正整数n的最小值.19.(本小题满分12分)如图,在三棱锥P−ABC中,侧面PAC⊥底面ABC,AC⊥BC,△PAC是边长为2的正三角形,BC=4,E,F分别是PC,PB的中点,记平面AEF与平面ABC的交线为l.(1)证明:直线l⊥平面PAC;(2)设点Q在直线l上,直线PQ与平面AEF所成的角为α,异面直线PQ与EF所成的π角为θ,求当AQ为何值时,α+θ=.2某社区消费者协会为了解本社区居民网购消费情况,随机抽取了100位居民作为样本,就最近一年来网购消费金额,网购次数和支付方式等进行了问卷调查.经统计,这100位居民的网购消费金额均在区间[0,30]内(单位:千元),按[0,5),(5,10],(10,15],(15,20],(20,25],[25,30]分成6组,其频率分布直方图如图所示.(1)估计该社区居民最近一年来网购消费金额的中位数;(2)将一年来网购消费金额在20千元以上者称为“网购迷”,补全下面的2×2列联表,并判断有多大把握认为“网购迷与性别有关系”;(3)调查显示,甲、乙两人每次网购采用的支付方式相互独立,两人网购时间与次数也互不影响.统计最近一年来两人网购的总次数与支付方式,所得数据如下表所示:网购总次数支付宝支付次数银行卡支付次数微信支付次数甲80401624乙90601812将频率视为概率,若甲、乙两人在下周内各自网购2次,记两人采用支付宝支付的次数之和为ξ,求ξ的数学期望.附:观测值公式:K 2=(a ()())(d )()(d ).2a b c +d ad bc b c +a c b ++-+++临界值表:P (K 2≥k 0)0.100.050.0250.0100.0050.001k 0 2.706 3.841 5.024 6.6357.87910.828已知抛物线E :x 2=2py (p >0)的焦点为F ,直线x=4分别与x 轴交于点P ,与抛物线E 交于点Q ,且54QF PQ =.(1)求抛物线E 的方程;(2)如图,设点A ,B ,C 都在抛物线E 上,若△ABC 是以AC 为斜边的等腰直角三角形, 求AB ⋅AC 的最小值.22.(本小题满分12分)已知函数f (x )=x 3+a ln x ,其中a ≥-3为常数.(1)设f '(x )为f (x )的导函数,当a=6时,求函数g (x )=f (x )-f '(x )+x9的极值;(2)设点A (x 1,f (x 1)),B (x 2,f (x 2))(x 1>x 2≥1),曲线y =f (x )在点A ,B 处的切线的斜率分别为k 1,k 2,直线AB 的斜率为k ,证明k 1+k 2>2k .。
2024-2025学年湖南师范大学附属中学高三上学期月考(一)数学试题及答案
大联考湖南师大附中2025届高三月考试卷(一)数学命题人:高三数学备课组 审题人:高三数学备课组时量:120分钟 满分:150分一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的,1. 已知{}()260,{lg 10}A x x xB x x =+-≤=-<∣∣,则A B = ( )A. {}32x x -≤≤∣ B. {32}xx -≤<∣C. {12}xx <≤∣ D. {12}xx <<∣2. 若复数z 满足()1i 3i z +=-+(i 是虚数单位),则z 等于( )A.B.54C.D.3. 已知平面向量()()5,0,2,1a b ==- ,则向量a b + 在向量b 上投影向量为( )A. ()6,3- B. ()4,2- C. ()2,1- D. ()5,04. 记n S 为等差数列{}n a 的前n 项和,若396714,63a a a a +==,则7S =( )A. 21B. 19C. 12D. 425. 某校高二年级下学期期末考试数学试卷满分为150分,90分以上(含90分)为及格.阅卷结果显示,全年级1200名学生的数学成绩近似服从正态分布,试卷的难度系数(难度系数=平均分/满分)为0.49,标准差为22,则该次数学考试及格的人数约为( )附:若()2,X Nμσ~,记()()p k P k X k μσμσ=-≤≤+,则()()0.750.547,10.683p p ≈≈.A 136人B. 272人C. 328人D. 820人6. 已知()π5,0,,cos ,tan tan 426αβαβαβ⎛⎫∈-=⋅= ⎪⎝⎭,则αβ+=( )A.π6 B.π4C.π3D.2π37. 已知12,F F 是双曲线22221(0)x y a b a b-=>>的左、右焦点,以2F 为圆心,a 为半径的圆与双曲线的一条的.渐近线交于,A B 两点,若123AB F F >,则双曲线的离心率的取值范围是( )A. ⎛ ⎝B. ⎛ ⎝C. (D. (8. 已知函数()220log 0x a x f x x x ⎧⋅≤=⎨>⎩,,,,若关于x 的方程()()0f f x =有且仅有两个实数根,则实数a 的取值范围是( )A. ()0,1 B. ()(),00,1-∞⋃ C. [)1,+∞ D. ()()0,11,+∞ 二、多选题:本题共3小题,每小题6分,共18分.在每小题给出的选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分9. 如图,在正方体111ABCD A B C D -中,E F M N ,,,分别为棱111AA A D AB DC ,,,的中点,点P 是面1B C 的中心,则下列结论正确的是( )A. E F M P ,,,四点共面B. 平面PEF 被正方体截得的截面是等腰梯形C. //EF 平面PMND. 平面MEF ⊥平面PMN10. 已知函数()5π24f x x ⎛⎫=+ ⎪⎝⎭,则( )A. ()f x 的一个对称中心为3π,08⎛⎫ ⎪⎝⎭B. ()f x 的图象向右平移3π8个单位长度后得到的是奇函数的图象C. ()f x 在区间5π7π,88⎡⎤⎢⎥⎣⎦上单调递增D. 若()y f x =在区间()0,m 上与1y =有且只有6个交点,则5π13π,24m ⎛⎤∈⎥⎝⎦11. 已知定义在R 上的偶函数()f x 和奇函数()g x 满足()()21f x g x ++-=,则()A. ()f x 的图象关于点()2,1对称B. ()f x 是以8为周期的周期函数C. ()20240g =D.20241(42)2025k f k =-=∑三、填空题:本题共3小题,每小题5分,共15分.12. 6(31)x y +-的展开式中2x y 的系数为______.13. 已知函数()f x 是定义域为R 的奇函数,当0x >时,()()2f x f x '->,且()10f =,则不等式()0f x >的解集为__________.14. 已知点C 为扇形AOB 弧AB 上任意一点,且60AOB ∠=,若(),R OC OA OB λμλμ=+∈,则λμ+的取值范围是__________.四、解答题:本题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.15. ABC V 的内角,,A B C 的对边分别为,,a b c ,已知22cos a b c B +=.(1)求角C ;(2)若角C 的平分线CD 交AB于点,D AD DB ==CD 的长.16. 已知1ex =为函数()ln af x x x =的极值点.(1)求a 的值;(2)设函数()ex kxg x =,若对()120,,x x ∀∈+∞∃∈R ,使得()()120f x g x -≥,求k 的取值范围.17. 已知四棱锥P ABCD -中,平面PAB ⊥底面,ABCD AD∥,,,2,BC AB BC PA PB AB AB BC AD E ⊥====为AB 的中点,F 为棱PC 上异于,P C 的点.的(1)证明:BD EF ⊥;(2)试确定点F 的位置,使EF 与平面PCD18. 在平面直角坐标系xOy 中,抛物线21:2(0)C y px p =>的焦点到准线的距离等于椭圆222:161C x y +=的短轴长,点P 在抛物线1C 上,圆222:(2)E x y r -+=(其中01r <<).(1)若1,2r Q =为圆E 上的动点,求线段PQ 长度的最小值;(2)设()1,D t 是抛物线1C 上位于第一象限的一点,过D 作圆E 的两条切线,分别交抛物线1C 于点,M N .证明:直线MN 经过定点.19. 龙泉游泳馆为给顾客更好的体验,推出了A 和B 两个套餐服务,顾客可选择A 和B 两个套餐之一,并在App 平台上推出了优惠券活动,下表是该游泳馆在App 平台10天销售优惠券情况.销售量千张经计算可得:10101021111 2.2,118.73,38510i i i i i i i y y t y t =======∑∑∑(1)因为优惠券购买火爆,App 平台在第10天时系统出现异常,导致当天顾客购买优惠券数量大幅减少,已知销售量y 和日期t 呈线性关系,现剔除第10天数据,求y 关于t 的经验回归方程结果中的数值用分数表示;(2)若购买优惠券的顾客选择A 套餐的概率为14,选择B 套餐的概率为34,并且A 套餐可以用一张优惠券,B 套餐可以用两张优惠券,记App 平台累计销售优惠券为n 张的概率为n P ,求n P ;(3)记(2)中所得概率n P 的值构成数列{}()N n P n *∈.①求n P 的最值;②数列收敛的定义:已知数列{}n a ,若对于任意给定的正数ε,总存在正整数0N ,使得当0n N >时,n a a ε-<,(a 是一个确定的实数),则称数列{}n a 收敛于a .根据数列收敛的定义证明数列{}n P 收敛..参考公式:()()()1122211ˆˆ,n ni i i ii in ni ii ix x y y x y nx ya y bxx x x nx====---==---∑∑∑∑.大联考湖南师大附中2025届高三月考试卷(一)数学命题人:高三数学备课组 审题人:高三数学备课组时量:120分钟 满分:150分一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的,1. 已知{}()260,{lg 10}A x x xB x x =+-≤=-<∣∣,则A B = ( )A. {}32x x -≤≤∣ B. {32}xx -≤<∣C. {12}xx <≤∣ D. {12}xx <<∣【答案】D 【解析】【分析】通过解一元二次不等式和对数函数的定义域,求出集合,A B ,再求交集.【详解】集合{}()32,{lg 10}{12}A x x B x x x x =-≤≤=-<=<<∣∣∣,则{12}A B xx ⋂=<<∣,故选:D .2. 若复数z 满足()1i 3i z +=-+(i 是虚数单位),则z 等于( )A.B.54C.D.【答案】C 【解析】【分析】由复数的除法运算计算可得12i z =-+,再由模长公式即可得出结果.【详解】依题意()1i 3i z +=-+可得()()()()3i 1i 3i 24i12i 1i 1i 1i 2z -+--+-+====-+++-,所以z ==.故选:C3. 已知平面向量()()5,0,2,1a b ==- ,则向量a b +在向量b 上的投影向量为( )A. ()6,3- B. ()4,2- C. ()2,1- D. ()5,0【答案】A 【解析】【分析】根据投影向量的计算公式即可求解.【详解】()()7,1,15,a b a b b b +=-+⋅=== 所以向量a b +在向量b 上的投影向量为()()236,3||a b b b b b +⋅==- .故选:A4. 记n S 为等差数列{}n a 的前n 项和,若396714,63a a a a +==,则7S =( )A. 21 B. 19C. 12D. 42【答案】A 【解析】【分析】根据等差数列的性质,即可求解公差和首项,进而由求和公式求解.【详解】{}n a 是等差数列,396214a a a ∴+==,即67a =,所以67769,a a a a ==故公差76162,53d a a a a d =-=∴=-=-,()767732212S ⨯∴=⨯-+⨯=,故选:A5. 某校高二年级下学期期末考试数学试卷满分为150分,90分以上(含90分)为及格.阅卷结果显示,全年级1200名学生的数学成绩近似服从正态分布,试卷的难度系数(难度系数=平均分/满分)为0.49,标准差为22,则该次数学考试及格的人数约为( )附:若()2,X Nμσ~,记()()p k P k X k μσμσ=-≤≤+,则()()0.750.547,10.683p p ≈≈.A. 136人B. 272人C. 328人D. 820人【答案】B 【解析】【分析】首先求出平均数,即可得到学生的数学成绩2~(73.5,22)X N ,再根据所给条件求出(5790)P X ≤≤,即可求出(90)P X ≥,即可估计人数.【详解】由题得0.4915073.5,22μσ=⨯==,()()(),0.750.547p k P k X k p μσμσ=-≤≤+≈ ,()5790P X ∴≤≤()0.750.547p =≈,()()900.510.5470.2265P X ≥=⨯-=,∴该校及格人数为0.22651200272⨯≈(人),故选:B .6. 已知()π5,0,,cos ,tan tan 426αβαβαβ⎛⎫∈-=⋅= ⎪⎝⎭,则αβ+=( )A.π6 B.π4C.π3D.2π3【答案】D 【解析】【分析】利用两角差的余弦定理和同角三角函数的基本关系建立等式求解,再由两角和的余弦公式求解即可.【详解】由已知可得5cos cos sin sin 6sin sin 4cos cos αβαβαβαβ⎧⋅+⋅=⎪⎪⎨⋅⎪=⋅⎪⎩,解得1cos cos 62sin sin 3αβαβ⎧⋅=⎪⎪⎨⎪⋅=⎪⎩,,()1cos cos cos sin sin 2αβαβαβ∴+=⋅-⋅=-,π,0,2αβ⎛⎫∈ ⎪⎝⎭,()0,παβ∴+∈,2π,3αβ∴+=,故选:D .7. 已知12,F F 是双曲线22221(0)x y a b a b-=>>的左、右焦点,以2F 为圆心,a 为半径的圆与双曲线的一条渐近线交于,A B 两点,若123AB F F >,则双曲线的离心率的取值范围是( )A. ⎛ ⎝B. ⎛ ⎝C. (D. (【答案】B 【解析】【分析】根据双曲线以及圆的方程可求得弦长AB =,再根据不等式123AB F F >整理可得2259c a <,即可求得双曲线的离心率的取值范围.【详解】设以()2,0F c 为圆心,a 为半径的圆与双曲线的一条渐近线0bx ay -=交于,A B 两点,则2F 到渐近线0bx ay -=的距离d b ==,所以AB =,因为123AB F F >,所以32c ⨯>,可得2222299a b c a b ->=+,即22224555a b c a >=-,可得2259c a <,所以2295c a <,所以e <,又1e >,所以双曲线的离心率的取值范围是⎛ ⎝.故选:B8. 已知函数()220log 0x a x f x x x ⎧⋅≤=⎨>⎩,,,,若关于x 的方程()()0f f x =有且仅有两个实数根,则实数a 的取值范围是( )A. ()0,1 B. ()(),00,1-∞⋃ C. [)1,+∞ D. ()()0,11,+∞ 【答案】C 【解析】【分析】利用换元法设()u f x =,则方程等价为()0f u =,根据指数函数和对数函数图象和性质求出1u =,利用数形结合进行求解即可.【详解】令()u f x =,则()0f u =.①当0a =时,若()0,0u f u ≤=;若0u >,由()2log 0f u u ==,得1u =.所以由()()0ff x =可得()0f x ≤或()1f x =.如图所示,满足()0f x ≤的x 有无数个,方程()1f x =只有一个解,不满足题意;②当0a ≠时,若0≤u ,则()20uf u a =⋅≠;若0u >,由()2log 0f u u ==,得1u =.所以由()()0ff x =可得()1f x =,当0x >时,由()2log 1f x x ==,可得2x =,因为关于x 的方程()()0f f x =有且仅有两个实数根,则方程()1f x =在(,0∞-]上有且仅有一个实数根,若0a >且()(]0,20,xx f x a a ≤=⋅∈,故1a ≥;若0a <且()0,20xx f x a ≤=⋅<,不满足题意.综上所述,实数a 的取值范围是[)1,+∞,故选:C .二、多选题:本题共36分,共18分.在每小题给出的选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分9. 如图,在正方体111ABCD A B C D -中,E F M N ,,,分别为棱111AA A D AB DC ,,,的中点,点P 是面1B C 的中心,则下列结论正确的是( )A. E F M P ,,,四点共面B. 平面PEF 被正方体截得的截面是等腰梯形C. //EF 平面PMND. 平面MEF ⊥平面PMN【答案】BD 【解析】【分析】可得过,,E F M 三点的平面为一个正六边形,判断A ;分别连接,E F 和1,B C ,截面1C BEF 是等腰梯形,判断B ;分别取11,BB CC 的中点,G Q ,易证EF 显然不平行平面QGMN ,可判断C ;EM ⊥平面PMN ,可判断D.【详解】对于A :如图经过,,E F M 三点的平面为一个正六边形EFMHQK ,点P 在平面外,,,,E F M P ∴四点不共面,∴选项A 错误;对于B :分别连接,E F 和1,B C ,则平面PEF 即平面1C BEF ,截面1C BEF 是等腰梯形,∴选项B 正确;对于C :分别取11,BB CC 的中点,G Q ,则平面PMN 即为平面QGMN ,由正六边形EFMHQK ,可知HQ EF ,所以MQ 不平行于EF ,又,EF MQ ⊂平面EFMHQK ,所以EF MQ W = ,所以EF I 平面QGMN W =,所以EF 不平行于平面PMN ,故选项C 错误;对于D :因为,AEM BMG 是等腰三角形,45AME BMG ∴∠=∠=︒,90EMG ∴∠=︒,EMMG ∴⊥,,M N 是,AB CD 的中点,易证MN AD ∥,由正方体可得AD ⊥平面11ABB A ,MN ∴⊥平面11ABB A ,又ME ⊂平面11ABB A ,EM MN ∴⊥,,MG MN ⊂ 平面PMN ,EM ∴⊥平面GMN ,EM ⊂ 平面MEF ,∴平面MEF ⊥平面,PMN 故选项D 正确.故选:BD .10. 已知函数()5π24f x x ⎛⎫=+ ⎪⎝⎭,则( )A. ()f x 的一个对称中心为3π,08⎛⎫ ⎪⎝⎭B. ()f x 的图象向右平移3π8个单位长度后得到的是奇函数的图象C. ()f x 在区间5π7π,88⎡⎤⎢⎥⎣⎦上单调递增D. 若()y f x =在区间()0,m 上与1y =有且只有6个交点,则5π13π,24m ⎛⎤∈ ⎥⎝⎦【答案】BD 【解析】【分析】代入即可验证A ,根据平移可得函数图象,即可由正弦型函数的奇偶性求解B ,利用整体法即可判断C ,由5πcos 24x ⎛⎫+= ⎪⎝⎭求解所以根,即可求解D.【详解】对于A ,由35π3π2π0848f ⎛⎫⎛⎫=+⨯=≠⎪ ⎪⎝⎭⎝⎭,故A 错误;对于B ,()f x 的图象向右平移3π8个单位长度后得:3π3π5ππ228842y f x x x x ⎡⎤⎛⎫⎛⎫⎛⎫=-=-+=+= ⎪ ⎪ ⎪⎢⎥⎝⎭⎝⎭⎝⎭⎣⎦,为奇函数,故B 正确;对于C ,当5π7π,88x ⎡⎤∈⎢⎥⎣⎦时,则5π5π2,3π42x ⎡⎤+∈⎢⎥⎣⎦,由余弦函数单调性知,()f x 在区间5π7π,88⎡⎤⎢⎥⎣⎦上单调递减,故C 错误;对于D ,由()1f x =,得5πcos 24x ⎛⎫+= ⎪⎝⎭ππ4x k =+或ππ,2k k +∈Z ,()y f x =在区间()0,m 上与1y =有且只有6个交点,其横坐标从小到大依次为:ππ5π3π9π5π,,,,,424242,而第7个交点的横坐标为13π4,5π13π24m ∴<≤,故D 正确.故选:BD11. 已知定义在R 上的偶函数()f x 和奇函数()g x 满足()()21f x g x ++-=,则( )A. ()f x 的图象关于点()2,1对称B. ()f x 是以8为周期的周期函数C. ()20240g =D.20241(42)2025k f k =-=∑【答案】ABC 【解析】【分析】根据函数奇偶性以及所满足的表达式构造方程组可得()()222f x f x ++-=,即可判断A 正确;利用对称中心表达式进行化简计算可得B 正确,可判断()g x 也是以8为周期的周期函数,即C 正确;根据周期性以及()()42f x f x ++=计算可得20241(42)2024k f k =-=∑,可得D 错误.【详解】由题意()()()(),f x f x g x g x -=-=-,且()()()00,21g f x g x =++-=,即()()21f x g x +-=①,用x -替换()()21f x g x ++-=中的x ,得()()21f x g x -+=②,由①+②得()()222f x f x ++-=所以()f x 的图象关于点(2,1)对称,且()21f =,故A 正确;由()()222f x f x ++-=,可得()()()()()42,422f x f x f x f x f x ++-=+=--=-,所以()()()()82422f x f x f x f x ⎡⎤+=-+=--=⎣⎦,所以()f x 是以8为周期的周期函数,故B 正确;由①知()()21g x f x =+-,则()()()()882121g x f x f x g x +=++-=+-=,故()()8g x g x +=,因此()g x 也是以8为周期的周期函数,所以()()202400g g ==,C 正确;又因为()()42f x f x ++-=,所以()()42f x f x ++=,令2x =,则有()()262f f +=,令10x =,则有()()10142,f f +=…,令8090x =,则有()()809080942f f +=,所以1012(2)(6)(10)(14)(8090)(8094)2222024f f f f f f ++++++=+++=个所以20241(42)(2)(6)(10)(14)(8090)(8094)2024k f k f f f f f f =-=++++++=∑ ,故D 错误.故选:ABC【点睛】方法点睛:求解函数奇偶性、对称性、周期性等函数性质综合问题时,经常利用其中两个性质推得第三个性质特征,再进行相关计算.三、填空题:本题共3小题,每小题5分,共15分.12. 6(31)x y +-的展开式中2x y 的系数为______.【答案】180-【解析】【分析】根据题意,由条件可得展开式中2x y 的系数为213643C C (1)⋅-,化简即可得到结果.【详解】在6(31)x y +-的展开式中,由()2213264C C 3(1)180x y x y ⋅⋅-=-,得2x y 的系数为180-.故答案为:180-.13. 已知函数()f x 是定义域为R 的奇函数,当0x >时,()()2f x f x '->,且()10f =,则不等式()0f x >的解集为__________.【答案】()()1,01,-⋃+∞【解析】【分析】根据函数奇偶性并求导可得()()f x f x ''-=,因此可得()()2f x f x '>,可构造函数()()2xf x h x =e并求得其单调性即可得()f x 在()1,+∞上大于零,在()0,1上小于零,即可得出结论.【详解】因为()f x 为奇函数,定义域为R ,所以()()f x f x -=-,两边同时求导可得()()f x f x ''--=-,即()()f x f x ''-=且()00f =,又因为当0x >时,()()2f x f x '->,所以()()2f x f x '>.构造函数()()2x f x h x =e ,则()()()22xf x f x h x '-'=e,所以当0x >时,()()0,h x h x '>在()0,∞+上单调递增,又因为()10f =,所以()()10,h h x =在()1,+∞上大于零,在()0,1上小于零,又因为2e 0x >,所以()f x 在()1,+∞上大于零,在()0,1上小于零,因为()f x 为奇函数,所以()f x 在(),1∞--上小于零,在()1,0-上大于零,综上所述,()0f x >的解集为()()1,01,-⋃+∞.故答案为:()()1,01,-⋃+∞14. 已知点C 为扇形AOB 的弧AB 上任意一点,且60AOB ∠=,若(),R OC OA OB λμλμ=+∈,则λμ+的取值范围是__________.【答案】⎡⎢⎣【解析】【分析】建系设点的坐标,再结合向量关系表示λμ+,最后应用三角恒等变换及三角函数值域求范围即可.【详解】方法一:设圆O 的半径为1,由已知可设OB 为x 轴的正半轴,O 为坐标原点,过O 点作x 轴垂线为y 轴建立直角坐标系,其中()()1,1,0,cos ,sin 2A B C θθ⎛ ⎝,其中π,0,3BOC θθ⎡⎤∠=∈⎢⎥⎣⎦,由(),R OC OA OB λμλμ=+∈,即()()1cos ,sin 1,02θθλμ⎛=+⎝,整理得1cos sin 2λμθθ+==,解得cos λμθ==,则ππcos cos ,0,33λμθθθθθ⎛⎫⎡⎤+==+=+∈ ⎪⎢⎥⎝⎭⎣⎦,ππ2ππ,,sin 3333θθ⎤⎡⎤⎛⎫+∈+∈⎥⎪⎢⎥⎣⎦⎝⎭⎦所以λμ⎡+∈⎢⎣.方法二:设k λμ+=,如图,当C 位于点A 或点B 时,,,A B C 三点共线,所以1k λμ=+=;当点C 运动到AB的中点时,k λμ=+==,所以λμ⎡+∈⎢⎣故答案为:⎡⎢⎣四、解答题:本题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.15. ABC V 的内角,,A B C 的对边分别为,,a b c ,已知22cos a b c B +=.(1)求角C ;(2)若角C 的平分线CD 交AB于点,D AD DB ==CD 的长.【答案】(1)2π3C = (2)3CD =【解析】【分析】(1)利用正弦定理及两角和的正弦定理整理得到()2cos 1sin 0C B +=,再利用三角形的内角及正弦函数的性质即可求解;(2)利用正弦定理得出3b a =,再由余弦定理求出4a =,12b =,再根据三角形的面积建立等式求解.【小问1详解】由22cos a b c B +=,根据正弦定理可得2sin sin 2sin cos A B C B +=,则()2sin sin 2sin cos B C B C B ++=,所以2sin cos 2cos sin sin 2sin cos B C B C B C B ++=,整理得()2cos 1sin 0C B +=,因为,B C 均为三角形内角,所以(),0,π,sin 0B C B ∈≠,因此1cos 2C =-,所以2π3C =.【小问2详解】因为CD 是角C的平分线,AD DB ==所以在ACD 和BCD △中,由正弦定理可得,,ππsin sin sin sin 33AD CD BD CDA B ==,因此sin 3sin B ADA BD==,即sin 3sin B A =,所以3b a =,又由余弦定理可得2222cos c a b ab C =+-,即222293a a a =++,解得4a =,所以12b =.又ABC ACD BCD S S S =+△△△,即111sin sin sin 222ab ACB b CD ACD a CD BCD ∠∠∠=⋅⋅+⋅⋅,即4816CD =,所以3CD =.16. 已知1ex =为函数()ln af x x x =的极值点.(1)求a 的值;(2)设函数()ex kxg x =,若对()120,,x x ∀∈+∞∃∈R ,使得()()120f x g x -≥,求k 的取值范围.【答案】(1)1a = (2)(]()10,-∞-+∞ ,【解析】【分析】(1)直接根据极值点求出a 的值;(2)先由(1)求出()f x 的最小值,由题意可得是求()g x 的最小值,小于等于()f x 的最小值,对()g x 求导,判断由最小值时的k 的范围,再求出最小值与()f x 最小值的关系式,进而求出k 的范围.【小问1详解】()()111ln ln 1a a f x ax x x x a x xα--=='+⋅+,由1111ln 10e e e a f a -⎛⎫⎛⎫⎛⎫=+= ⎪ ⎪⎪⎝⎭⎝⎭'⎭⎝,得1a =,当1a =时,()ln 1f x x ='+,函数()f x 在10,e ⎛⎫ ⎪⎝⎭上单调递减,在1,e∞⎛⎫+ ⎪⎝⎭上单调递增,所以1ex =为函数()ln af x x x =的极小值点,所以1a =.【小问2详解】由(1)知min 11()e e f x f ⎛⎫==- ⎪⎝⎭.函数()g x 的导函数()()1exg x k x -=-'①若0k >,对()1210,,x x k ∞∀∈+∃=-,使得()()12111e 1e k g x g f x k ⎛⎫=-=-<-<-≤ ⎪⎝⎭,即()()120f x g x -≥,符合题意.②若()0,0k g x ==,取11ex =,对2x ∀∈R ,有()()120f x g x -<,不符合题意.③若0k <,当1x <时,()()0,g x g x '<在(),1∞-上单调递减;当1x >时,()()0,g x g x '>在(1,+∞)上单调递增,所以()min ()1ek g x g ==,若对()120,,x x ∞∀∈+∃∈R ,使得()()120f x g x -≥,只需min min ()()g x f x ≤,即1e ek ≤-,解得1k ≤-.综上所述,k 的取值范围为(](),10,∞∞--⋃+.17. 已知四棱锥P ABCD -中,平面PAB ⊥底面,ABCD AD ∥,,,2,BC AB BC PA PB AB AB BC AD E ⊥====为AB 的中点,F 为棱PC 上异于,P C 的点.(1)证明:BD EF ⊥;(2)试确定点F 的位置,使EF 与平面PCD【答案】(1)证明见解析(2)F 位于棱PC 靠近P 的三等分点【解析】【分析】(1)连接,,PE EC EC 交BD 于点G ,利用面面垂直的性质定理和三角形全等,即可得证;(2)取DC 的中点H ,以E 为坐标原点,分别以,,EB EH EP 所在直线为,,x y z 轴建立,利用线面角公式代入即可求解.小问1详解】如图,连接,,PE EC EC 交BD 于点G .因为E 为AB 的中点,PA PB =,所以PE AB ⊥.因为平面PAB ⊥平面ABCD ,平面PAB ⋂平面,ABCD AB PE =⊂平面PAB ,所以PE ⊥平面ABCD ,因为BD ⊂平面ABCD ,所以BD ⊥.因为ABD BCE ≅ ,所以CEB BDA ∠∠=,所以90CEB ABD ∠∠+= ,所以BD EC ⊥,因为,,PE EC E PE EC ⋂=⊂平面PEC ,所以BD ⊥平面PEC .因为EF ⊂平面PEC ,所以BD EF ⊥.【小问2详解】如图,取DC 的中点H ,以E 为坐标原点,分别以,,EB EH EP 所在直线为,,x y z 轴建立空间直角坐标系,【设2AB =,则2,1,BC AD PA PB ====则()()()()0,0,1,1,2,0,1,1,0,0,0,0P C D E -,设(),,,(01)F x y z PF PC λλ=<<,所以()(),,11,2,1x y z λ-=-,所以,2,1x y z λλλ===-,即(),2,1F λλλ-.则()()()2,1,0,1,2,1,,2,1DC PC EF λλλ==-=-,设平面PCD 的法向量为(),,m a b c =,则00DC m PC m ⎧⋅=⎪⎨⋅=⎪⎩,,即2020a b a b c +=⎧⎨+-=⎩,,取()1,2,3m =--,设EF 与平面PCD 所成的角为θ,由cos θ=sin θ=.所以sin cos ,m EF m EF m EF θ⋅====整理得2620λλ-=,因为01λ<<,所以13λ=,即13PF PC = ,故当F 位于棱PC 靠近P 的三等分点时,EF 与平面PCD18. 在平面直角坐标系xOy 中,抛物线21:2(0)C y px p =>的焦点到准线的距离等于椭圆222:161C x y +=的短轴长,点P 在抛物线1C 上,圆222:(2)E x y r -+=(其中01r <<).(1)若1,2r Q =为圆E 上的动点,求线段PQ长度的最小值;(2)设()1,D t 是抛物线1C 上位于第一象限的一点,过D 作圆E 的两条切线,分别交抛物线1C 于点,M N .证明:直线MN 经过定点.【答案】(1(2)证明见解析【解析】【分析】(1)根据椭圆的短轴可得抛物线方程2y x =,进而根据两点斜率公式,结合三角形的三边关系,即可由二次函数的性质求解,(2)根据两点坐标可得直线,MN DM 的直线方程,由直线与圆相切可得,a b 是方程()()()2222124240r x r x r -+-+-=的两个解,即可利用韦达定理代入化简求解定点.【小问1详解】由题意得椭圆的方程:221116y x +=,所以短半轴14b =所以112242p b ==⨯=,所以抛物线1C 的方程是2y x =.设点()2,P t t ,则111222PQ PE ≥-=-=≥,所以当232ι=时,线段PQ.【小问2详解】()1,D t 是抛物线1C 上位于第一象限的点,21t ∴=,且()0,1,1t D >∴设()()22,,,M a a N b b ,则:直线()222:b a MN y a x a b a --=--,即()21y a x a a b-=-+,即()0x a b y ab -++=.直线()21:111a DM y x a --=--,即()10x a y a -++=.由直线DMr =,即()()()2222124240r a r a r -+-+-=..同理,由直线DN 与圆相切得()()()2222124240r b r b r -+-+-=.所以,a b 是方程()()()2222124240r x r x r -+-+-=的两个解,22224224,11r r a b ab r r --∴+==--代入方程()0x a b y ab -++=得()()222440x y r x y +++---=,220,440,x y x y ++=⎧∴⎨++=⎩解得0,1.x y =⎧⎨=-⎩∴直线MN 恒过定点()0,1-.【点睛】圆锥曲线中定点问题的两种解法(1)引进参数法:先引进动点的坐标或动线中系数为参数表示变化量,再研究变化的量与参数何时没有关系,找到定点.(2)特殊到一般法:先根据动点或动线的特殊情况探索出定点,再证明该定点与变量无关.技巧:若直线方程为()00y y k x x -=-,则直线过定点()00,x y ;若直线方程为y kx b =+ (b 为定值),则直线过定点()0,.b 19. 龙泉游泳馆为给顾客更好的体验,推出了A 和B 两个套餐服务,顾客可选择A 和B 两个套餐之一,并在App 平台上推出了优惠券活动,下表是该游泳馆在App 平台10天销售优惠券情况.日期t 12345678910销售量千张 1.9 1.98 2.2 2.36 2.43259 2.682.76 2.70.4经计算可得:10101021111 2.2,118.73,38510i i i i i i i y y t y t =======∑∑∑.(1)因为优惠券购买火爆,App 平台在第10天时系统出现异常,导致当天顾客购买优惠券数量大幅减少,已知销售量y 和日期t 呈线性关系,现剔除第10天数据,求y 关于t 的经验回归方程结果中的数值用分数表示;..(2)若购买优惠券的顾客选择A 套餐的概率为14,选择B 套餐的概率为34,并且A 套餐可以用一张优惠券,B 套餐可以用两张优惠券,记App 平台累计销售优惠券为n 张的概率为n P ,求n P ;(3)记(2)中所得概率n P 的值构成数列{}()Nn P n *∈.①求n P 的最值;②数列收敛的定义:已知数列{}n a ,若对于任意给定的正数ε,总存在正整数0N ,使得当0n N >时,n a a ε-<,(a 是一个确定的实数),则称数列{}n a 收敛于a .根据数列收敛的定义证明数列{}n P 收敛.参考公式: ()()()1122211ˆˆ,n ni i i i i i n n ii i i x x y y x y nx y ay bx x x x nx ====---==---∑∑∑∑.【答案】(1)673220710001200y t =+ (2)433774n n P ⎛⎫=+⋅- ⎪⎝⎭(3)①最大值为1316,最小值为14;②证明见解析【解析】【分析】(1)计算出新数据的相关数值,代入公式求出 ,ab 的值,进而得到y 关于t 的回归方程;(2)由题意可知1213,(3)44n n n P P P n --=+≥,其中12113,416P P ==,构造等比数列,再利用等比数列的通项公式求解;(3)①分n 为偶数和n 为奇数两种情况讨论,结合指数函数的单调性求解;②利用数列收敛的定义,准确推理、运算,即可得证.【小问1详解】解:剔除第10天的数据,可得 2.2100.4 2.49y ⨯-==新,12345678959t ++++++++==新,则9922111119.73100.4114,73,38510285i i i i t y t ==⎛⎫⎛⎫=-⨯==-= ⎪ ⎪⎝⎭⎝⎭∑∑新新,所以912922119114,7395 2.4673ˆ2859560009i i i i t y t y b t t ==⎛⎫- ⎪-⨯⨯⎝⎭===-⨯⎛⎫- ⎪⎝⎭∑∑新新新新新,可得6732207ˆ 2.4560001200a =-⨯=,所以6732207ˆ60001200y t =+.【小问2详解】解:由题意知1213,(3)44n n n P P P n --=+≥,其中12111313,444416P P ==⨯+=,所以11233,(3)44n n n n P P P P n ---+=+≥,又由2131331141644P P +=+⨯=,所以134n n P P -⎧⎫+⎨⎬⎩⎭是首项为1的常数列,所以131,(2)4n n P P n -+=≥所以1434(2)747n n P P n --=--≥,又因为1414974728P -=-=-,所以数列47n P ⎧⎫-⎨⎬⎩⎭是首项为928-,公比为34-的等比数列,故143)74n n P --=-,所以1934433(()2847774n n n P -=--+=+-.【小问3详解】解:①当n 为偶数时,19344334()(28477747n n n P -=--+=+⋅>单调递减,最大值为21316P =;当n 为奇数时,19344334()(28477747n n n P -=--+=-⋅<单调递增,最小值为114P =,综上可得,数列{}n P 的最大值为1316,最小值为14.②证明:对任意0ε>总存在正整数0347[log ()]13N ε=+,其中 []x 表示取整函数,当 347[log ()]13n ε>+时,347log ()34333333()()()7747474n n n P εε-=⋅-=⋅<⋅=,所以数列{}n P 收敛.【点睛】知识方法点拨:与新定义有关的问题的求解策略:1、通过给出一个新的定义,或约定一种新的运算,或给出几个新模型来创设新问题的情景,要求在阅读理解的基础上,依据题目提供的信息,联系所学的知识和方法,实心信息的迁移,达到灵活解题的目的;2、遇到新定义问题,应耐心读题,分析新定义的特点,弄清新定义的性质,按新定义的要求,“照章办事”,逐条分析、运算、验证,使得问题得以解决.方法点拨:与数列有关的问题的求解策略:3、若新定义与数列有关,可得利用数列的递推关系式,结合数列的相关知识进行求解,多通过构造的分法转化为等差、等比数列问题求解,求解过程灵活运用数列的性质,准确应用相关的数列知识.。
湖南省师大附中2014届高三上学期第一次月考生物试题 word版含答案
湖南师大附中2014届高三月考试卷(一)生 物一.选择题(每小题2分,共36分)1.某化合物含C 、H 、O 、N 、S 等元素,下列哪项最不可能...是它的功能 ( )A .在特定位点上切割基因B .抵抗病毒引起的感染C .促进新陈代谢、使机体产热增加、促进生长发育D .降低血糖2.下列与“同位素标记法”有关的说法正确的是 ( )A.用15N 标记核苷酸探明了分裂期染色体形态和数目的变化规律B.用18O 分别标记H 2O 和CO 2,分析释放的氧气,证明了CO 2是光合作用的原料C.用35S 标记噬菌体的DNA 并以此侵染细菌证明了DNA 是遗传物质D.用14C 标记CO 2最终探明了CO 2中的碳元素在光合作用中的转移途径3.下列生物学实验的原理、技术或方法正确的是( )A .“观察DNA 和RNA 在细胞中的分布”实验步骤为:制作装片→水解→染色→冲洗→观察B .斐林试剂与双缩脲试剂的配方完全相同C .NaOH 溶液在大小不同的琼脂块内扩散的速率相同D .用荧光标记的小鼠细胞和人细胞融合的实验证明细胞膜上的所有分子都可以随意运动4.某50肽中有丙氨酸(R 基为—CH 3)4个,现脱掉其中的丙氨酸(相应位置如图)得到4条多肽链和5个氨基酸(脱下的氨基酸均以游离态正常存在)。
下列有关叙述错误的是( )A .该50肽水解得到的几种有机物比原50肽增加了4个氧原子B .若将得到的5个氨基酸缩合成5肽,则有5种不同的氨基酸序列C .若新生成的4条多肽链总共有5个羧基,那么其中必有1个羧基在R 基上D .若将新生成的4条多肽链重新连接成一条长链将脱去3个H 2O5.6.下列模式图表示几种细胞器,有关说法正确的是A .A 、B 、C 、D 、E 、F 中都含有蛋白质 B .绿色植物的细胞都含有A 、C 、D 、E 、F C .B 、E 分别是动、植物细胞特有的细胞器 D .F 与D 间的相互转化能体现生物膜的流动性7.对绿色植物细胞某细胞器组成成分进行分析,发现A 、T 、C 、G 、U 五种碱基的相对含量分别约为35%、0、30%、20%、15%,则该细胞器能完成的生理活动是( )A. 吸收氧气,进行有氧呼吸B.发出星射线,形成纺锤体C. 结合mRNA,合成蛋白质D.吸收并转换光能,完成光合作用放大A B C D E F加入ATP 加入某药物 注入24Na +时间1 22 溶液中 的量 24Na + 1 0 + 8.细胞是生物体结构和功能的基本单位。
2014年高考湖南师大附中2014届高三第六次月考
2014年高考(130)湖南师大附中2014届高三第六次月考高考模拟2014-02-26 2150湖南师大附中2014届高三月考试卷(六)语文试题一、语言文字运用(12分,每小题3分)1.下列词语中,加点的字读音全都正确的一项是A.躯壳(qiào)横财(hãng)倾轧(yà)乘人之危(chãng)B.勾当(gòu)沏茶(qī)胡诌(zhōu)自怨自艾(yì)C.间距(jiān)稽首(jī)蜃景(shân)翘首以待(qiáo)D.道观(guàn)着落(zhuó)龟裂(jūn)荷枪实弹(hã)2.下列词语中没有错别字的一项是A.编篡节骨眼和盘托出计日成功B.祛除泊来品铃牙俐齿焚膏继晷C.统制手榴弹绿草如茵万事亨通D.缜密绊脚石翻云覆雨改弦更张3.下列各句中,没有语病的一项是A.北京警方启动代号为“平安春运”的春运安全保卫,对铁道、公路、民航的客流进行动态监测,一旦发生旅客、车辆滞留,将增派警力进行疏导。
B.中韩两国在经济上关系密切,据韩国知识经济部发布的最新数据显示,2014年中韩贸易总额达到2139.2亿美元,占韩国全年贸易总额的19.77%。
C.广电总局下发管理办法,要求全国各地电视台自2014年1月起,每集电视剧中间不得再以任何形式插播广告。
这一规定能更好地满足观众的愿望。
D.奇幻文学之所以能得到广大读者的喜爱,是因为正义战胜邪恶、英雄创造历史的主旋律,正好暗合了人们心灵深处对英雄的呼唤,对正义的渴望。
4.在两个横横线处,分别填入一句符合情境,富有寓意的话,最恰当的一项是孩子手拿一个橘子问:“妈妈,橘子为什么不能拿来就吃,先要剥皮,这么麻烦呢?”妈妈说::“孩子,那是橘子在告诉你:①。
”孩子又问:“妈妈,橘子的果肉为什么是分成一小块一小块的,而不是一个完整的呢?”妈妈说:“孩子,那是橘子承告诉你:②。
2024届湖南师范大学附属中学高三上学期月考卷(四)数学及答案
湖南师大附中2024届高三月考试卷(四)数学审题人:高三备课组时量:120分钟 满分:150分一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知复数12i z =+,其中i 为虚数单位,则复数2z 在复平面内对应的点的坐标为( )A.(4,5)- B.(4,3)C.(3,4)- D.(5,4))2.若随机事件A ,B 满足1()3P A =,1()2P B =,3()4P A B = ,则(|)P A B =( )A.29B.23C.14D.168.设{}n a 是公比不为1的无穷等比数列,则“{}n a 为递减数列”是“存在正整数0N ,当0n N >时,1n a <”的()A.充分而不必要条件B.必要而不充分条件C.充分必要条件D.既不充分也不必要条件4.设0,2πα⎛⎫∈ ⎪⎝⎭,0,2πβ⎛⎫∈ ⎪⎝⎭,且1tan tan cos αβα+=,则( )A.22παβ+=B.22παβ-=C.22πβα-=D.22πβα+=5.若52345012345(12)(1)(1)(1)(1)(1)x a a x a x a x a x a x -=+-+-+-+-+-,则下列结论中正确的是( )A.01a = B.480a =C.50123453a a a a a a +++++= D.()()10024135134a a a a a a -++++=6.函数1()2cos[(2023)]|1|f x x x π=++-在区间[3,5]-上所有零点的和等于( )A.2B.4C.6D.87.点M 是椭圆22221x y a b+=(0a b >>)上的点,以M 为圆心的圆与x 轴相切于椭圆的焦点F ,圆M 与y 轴相交于P ,Q ,若PQM △是钝角三角形,则椭圆离心率的取值范围是()A.(0,2B.⎛ ⎝C.⎫⎪⎪⎭D.(2-8.已知函数22,0,()4|1|4,0,x x f x x x ⎧=⎨-++<⎩…若存在唯一的整数x ,使得()10f x x a -<-成立,则所有满足条件的整数a 的取值集合为( )A.{2,1,0,1}-- B.{2,1,0}-- C.{1,0,1}- D.{2,1}-二、选择题:本题共4小题,每小题5分,共20分.在每小题给出的选项中,有多项符合题目要求.全部选对的得5分,部分选对的得2分,有选错的得0分、9.已.知双曲线C过点且渐近线为y x =,则下列结论正确的是( )A.C 的方程为2213x y -= B.CC.曲线2e1x y -=-经过C 的一个焦点D.直线10x --=与C 有两个公共点10.已知向量a ,b满足|2|||a b a += ,20a b a ⋅+= 且||2a = ,则( )A.||8b = B.0a b += C.|2|6a b -=D.4a b ⋅= 11.如图、正方体1111ABCD A B C D -的棱长为2,点M 是其侧面11ADD A 上的一个动点(含边界),点P 是线段1CC 上的动点,则下列结论正确的是()A.存在点P ,M ,使得二面角M DC P --大小为23πB.存在点P ,M ,使得平面11B D M 与平面PBD 平行C.当P 为棱1CC的中点且PM =时,则点M 的轨迹长度为23πD.当M 为1A D 中点时,四棱锥M ABCD -12.若存在实常数k 和b ,使得函数()F x 和()G x 对其公共定义域上的任意实数x 都满足:()F x kx b +…和()G x kx b +…恒成立,则称此直线y kx b =+为()F x 和()G x 的“隔离直线”.已知函数2()f x x =(x ∈R ),1()g x x=(0x <),()2eln h x x =(e 2.718≈),则下列选项正确的是( )A.()()()m x f x g x =-在x ⎛⎫∈ ⎪⎝⎭时单调递增B.()f x 和()g x 之间存在“隔离直线”,且b 的最小值为–4C.()f x 和()g x 之间存在“隔离直线”,且k 的取值范围是[4,1]-D.()f x 和()h x之间存在唯一的“隔离直线”ey =-三、填空题:本题共4小题,每小题5分,共20分.13.已知函数()y f x =的图象在点(1,(1))M f 处的切线方程是122y x =+,则(1)(1)f f +'=___________.14.如图,由3个全等的钝角三角形与中间一个小等边三角形DEF 拼成的一个较大的等边三角形ABC ,若3AF =,sin ACF ∠=,则DEF △的面积为___________.15.已知数列{}n a 的首项132a =,且满足1323n n n a a a +=+.若123111181n a a a a ++++< ,则n 的最大值为___________.16.在棱长为3的正方体1111ABCD A B C D -中,点E 满足112A E EB =,点F 在平面1BC D 内,则|1||A F EF +的最小值为___________.四、解答题:本题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.(10分)已知函数2()2cos 2xf x x m ωω=++(0ω>)的最小值为–2.(1)求函数()f x 的最大值;(2)把函数()y f x =的图象向右平移6πω个单位长度,可得函数()y g x =的图象,且函数()y g x =在0,8π⎡⎤⎢⎥⎣⎦上单调递增,求ω的最大值.18.(12分)为了丰富在校学生的课余生活,某校举办了一次趣味运动会活动,学校设置项目A “毛毛虫旱地龙舟”和项目B “袋鼠接力跳”.甲、乙两班每班分成两组,每组参加一个项目,进行班级对抗赛.第一个比赛项目A 采取五局三胜制(即有一方先胜3局即获胜,比赛结束);第二个比赛项目B 采取领先3局者获胜。
最新湖南师大附中届高三月考试卷(9)资料讲解
一、选择题:本大题共 10 小题,每小题 5 分,共 50 分,在每小题的四个选项中,只有一 项是符合题目要求的
1.设集合 M x x 3n 1, n Z , N y y 3n 1, n Z ,若 x0 M , y0 N ,则 x0 y0
2
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abcd 1cd cd c10 c c2 10c c 52 25 , 2 c 4 ,
16 c 52 25 24 ,即16 abcd 24 .
2.设 p: 2x 1 0 ,q: ( x a) x (a 1) 0 ,若 q 是 p 的必要而不充分条件,
x1
则实数 a 的取值范围是( )
A.
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【答案】A
B.
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D. ,0
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【解析】解不等式 2 x 1 0 得: 1 x 1 ,故满足命题 p 的集合 P=( 1 ,1),解不等式
1 x2 5x 12 0 , 即 x2 10x 24 0 , 解 得 x 4 或 x 6 , 而 二 次 函 数 2
y 1 x2 5x 12 的图象的对称轴为直线 x 5 ,由图象知, 2 c 4 ,点 c, f c 和点 2
d, f d 均在二次函数 y 1 x2 5x 12 的图象上,故有 c d 5 ,d 10 c ,
,
D ,双曲线的右顶点为 E , CED 1500 ,其双曲线的离心率为(
)
A. 2 3 9
【答案】D
B. 3 2
C. 3
D. 2 3 3
【解析】由∠CED=150°,∴∠CEO=75°,∵OC=OE,∴∠OCE=75°,∴∠ECF=15°,
湖南师大附中2014届高三月考试卷(七)理科数学
湖南师大附中2014届高三月考试卷(七)数学(理科)总分:150分 时量:120分钟一、选择题:本大题共10小题,每小题5分,共50分.在每小题给出的四个选项中,只有一项是符合题目要求的,请将所选答案填在答题卡中对应位置.1.已知i 为虚数单位,则31ii-=+( )A. 12i +B. 1i +C. 1i -D. 12i - 2.在ABC ∆中,若2cos a b C =,则ABC ∆是( )A. 锐角三角形B. 等腰三角形C. 钝角三角形D. 直角三角形 3.如下图,某几何体的正视图与侧视图都是边长为1的正方形,且体积为12,则该几何体的俯视图可以是( )4.已知,x y 满足,2,y x x y x a ≥⎧⎪+≤⎨⎪≥⎩目标函数2z x y =+的最大值为M ,最小值为N ,且4M N =,则a 的值是( ) A. 13B. 14C. 15D. 165.若不等式[(1)]lg 0a n a a --<对任意正整数n 恒成立,则实数a 的取值范围是( )A. 1a >B. 102a <<C. 102a <<或1a >D. 103a <<或1a >6.右图是某同学为求1007个偶数:2,4,6,…,2014的平均数而设计的程序框图的部分内容,则在该程序框图中的空白判断框和处理框 中应填入的内容依次是( )A. 1007?1007x i x >=B. 1007?1007xi x ≥=C. 1007?1007x i x <=D. 1007?1007xi x ≤=7.已知22()|1|f x x x kx =-++,若关于x 的方程()0f x =在(0,2)上有 两个不相等的实根,则k 的取值范围是( )A. (1,0)-B. 7(,)2-+∞C. 7(,)(1,)2-∞--+∞D. 7(,1)2--A 正视图侧视图B C D8.已知在等差数列{}n a 中,201320140,,d a a >是方程2350x x --=的两个根,那么使得前n 项和n S 为负值的最大的n 的值是( )A. 2013B. 2014C. 4025D. 40269.设,P Q是双曲线22x y -=上关于原点O 对称的两点,将坐标平面沿双曲线的一条渐近线l 折成直二面角,则折叠后线段PQ 长的最小值为( )A.B.C. D. 410.已知满足条件221x y +≤的点(,)x y 构成的平面区域的面积为1S ,满足条件22[][]1x y +≤点(,)x y 构成的平面区域的面积为2S (其中[][]x y 、分别表示不大于,x y 的最大整数),则点12(,)S S 一定在( )A. 直线0x y -=上B. 直线210x y --=右下方的区域内C. 直线80x y +-=左下方的区域内D. 直线20x y -+=左上方的区域内二、填空题:本大题共6小题,考生作答5小题,每小题5分,共25分,把答案填在答题卡中对应题号后的横线上. (一)选做题(请考生在11、12、13三题中任选两题作答,如果全做,则按前两题记分)11.(极坐标与参数方程)在直角坐标系xOy 中,直线l 的参数方程为,(1x t t y kt =⎧⎨=+⎩为参数),以O 为原点,Ox 轴为极轴,单位长度不变,建立极坐标系,曲线C 的极坐标方程为: 2sin 4cos ρθθ=,若直线l 和曲线C 相切,则实数k 的值为 .12.(几何证明选讲:2012•佛山一模)如图,P 为圆O 外一点,由P引圆O 的切线PA 与圆O 切于A 点,引圆O 的割线PB 与圆O 交于C 点.已知,2,1AB AC PA PC ⊥==,则圆O 的面积为 . 13.(不等式选讲)若不等式|1|22a x y z -≥++,对满足2221x y z ++= 的一切实数,,x y z 恒成立,则实数a 的取值范围是 . (二)必做题(14 ~16题)14.如图所示,在一个边长为1的正方形AOBC 内,曲线2y x =和曲线y (阴影部分),向正方形AOBC 内 随机投一点(该点落在正方形AOBC 内任何一点是等可能的), 则所投的点落在叶形图内部的概率是 .15.在ABC ∆中有如下结论:“若点M 为ABC ∆的重心,则MA MB MC ++=0”,设,,a b c 分别为ABC ∆的内角,,A B C 的对边,点M 为ABC ∆的重心.如果aMA bMB cMC +=0,则内角A 的大小为 ;若3a =,则ABC ∆的面积为 .16.(03 年全国卷)设数列{}n a 是集合{22|0s t s t +≤<,且,}s t Z ∈中所有的数从小到大排列成的数列,即1233,5,6,a a a === 4569,10,12,a a a === ,将数列{}n a 各项按照“上小下大,左小右大”的原则写成如右的三角形数表:(1)这个三角形数表的第四行各数从左到右依次为 ; (2)100a = .B CP三、解答题:本大题共6小题,共75分.解答应写出文字说明,证明过程或演算步骤. 17.(本小题满分12分)已知向量(2cos ,cos ),,2cos )x x x x ==a b ,函数()3f x =⋅+a b .(Ⅰ)当(0,)2x π∈时,求函数()f x 的值域;(Ⅱ)若28()5f x =,且5(,)612x ππ∈,求cos(2)12x π-的值.18.(本小题满分12分)某高中社团进行社会实践,对[25,55]岁的人群随机抽取n 人进行了一次是否开通“ 微博”的调查,若开通“微博”的称为“时尚族”,否则称为“非时尚族”.通过调查分别得到如图1所(Ⅱ)从[40,45)和[45,50)岁年龄段的“时尚族”中采用分层抽样法抽取18人参加网络时尚达人大赛,其中选取3人作为邻队,若选取的3名领队年龄在[40,45)岁的人数为X ,求X 的分布列和期望()E X .19.(本小题满分12分)(2013·盐城三模)如图,三棱锥P ABC -中,已知PA ⊥平面,ABCABC ∆是边长为2的正三角形,,D E 分别为,PB PC 中点. (Ⅰ)若2,PA =求直线AE 与PB 所成角的余弦值; (Ⅱ)若平面ADE ⊥平面PBC ,求PA 的长.AD CB EP20.(本小题满分13分)由于澳大利亚只有一些袋类低级动物,兔子在这里称王称霸,无限制地繁殖,并与牛羊争草吃,使得全澳牧业损失掺重.澳大利亚政府为维持生态平衡,需从宏观上考察兔子的再生能力及捕杀强度对免子总量的影响,用n x 表示兔子在第*()n n N ∈年年初的总量,且10x >,不考虑其它因素,设在第n 年内兔子的繁殖量及被捕杀量都与n x 成正比,死亡量与2n x 成正比,这些比例系数依次为正常数,,.a b c (Ⅰ)求1n x +与n x 的关系式;(Ⅱ)若2,1a c ==,为保证对任意1(0,2)x ∈,都有*0,n x n N >∈,则捕杀强度b 的最大允许值是多少?证明你的结论. 21.(本小题满分13分) 如图,HIJK 是边长为2的正方形纸片,沿某动直线l 为折痕 将正方形在其下方的部分向上翻折后点I 都落在边HK 上,记为I ',折痕l 与HI 交于点E ,点M 满足关系式EM EI EI '=+ .若以 I 为原点,IJ 所在直线为x 轴建立平面直角坐标系(如图).(Ⅰ)求点M 的轨迹C 的方程;(Ⅱ)若将轨迹C 的方程中的x 的范围扩充为全体实数R ,得到曲线L 的方程,再将曲线L 的图象先向下平移一个单位,然后沿直线y x =轴翻折,最后每个点的横坐标伸长为原来的两倍(纵坐标不变)得到曲线D 的图象,设Q 为曲线D 上的一个动点,点B C 、在y 轴上,若QBC ∆为圆22(1)1x y ++=的外切三角形,求QBC ∆面积的最小值.22.(本小题满分13分)已知函数3(),()2,x x f x e e g x x ax a -=+=+为实常数. (Ⅰ)求()f x 在区间[1,ln 2]-上的最大值;(Ⅱ)当1a =-时,证明:0x R ∃∈,使得()y f x =和()y g x =的图象在0x x =处的切线互相平行; (Ⅲ)若对任意x R ∈不等式()'()f x g x ≥恒成立,求a 的取值范围.参考答案一、选择题D B C B C ;A D C D B 二、填空题11. 1. 12.94π. 13.4a ≥或2a ≤-. 14.13. 15.6π. 16.(1)17,18,20,24;(2)16640.三、解答题17.【解】(Ⅰ)由已知2()22cos 32cos24f x x x x x =++=++ 2sin(2)46x π=++…………………………………………………3分当(0,)2x π∈时,72(,)666x πππ+∈,故1sin(2)(,1]62x π+∈-.故函数()f x 的值域为(3,6]………………………………………………………………6分(Ⅱ)由28()5f x =,得282sin(2)465x π++=,即4sin(2)65x π+=. 因为5(,)612x ππ∈,则2(,)62x πππ+∈,所以3cos(2)5x π+=-…………………………8分故cos(2)cos[(2)]cos(2)sin(212646x x x x πππππ-=+-=+++=………12分 18.【解】(Ⅰ)依题分布直方图知第二组的频率为 21(0.040.040.030.020.0f =-++++⨯= 所以第二组的高为220.065f h ==,频率分布直方 图如右所示:又结合表(1)知第一组的人数为1202000.6=,又10.0450.2f =⨯=,所以样本容量为1200n f == 又第二组的人数有221000300n f =⨯=,故1950.65300p ==……………………………4分同理第四组人数有41000(0.035)150n =⨯⨯=人,故1500.460a =⨯=………………5分 (Ⅱ)因为[40,45)岁和[45,50)岁年龄段的“时尚族”的人数比值为60:302:1=,所以采用分层抽样法抽取18人,[40,45)岁中有12人,[45,50)岁中有6人,…………6分 故随机变量X 服从超几何分布.X 的所有可能值为0,1,2,3.且0312********1818515(0),(1),20468C C C C P X P X C C ====== 21301261263318183355(2),(3),68204C C C C P X P X C C ====== 所以随机变量X 的分布列为 所以数学期望5153355()012322046868205E X =⨯+⨯+⨯+⨯=…………………………………………12分 19.【解】(Ⅰ)如图,取AC 中点F ,连接BF ,则BF AC ⊥,以A 为坐标原点,过A 且与FB 平行的直线为x 轴,AC 为y 轴, AP 为z 轴,建立空间直角坐标系 (2)则(0,0,0),(0,2,0),(0,0,2),(0,1,1)A B C P E ,从而有 ,1,2),(0,1,1)P B A E =-=,设直线AE 与PB 所成的角为 θ,则||1cos 4||||PB AE PB AE θ⋅==⨯,即直线AE 与PB 所成角的余 弦值为14.……………………………………………………6分(Ⅱ)设0PA a =>,则(0,0,)P a ,从而),PB a =-(0,2,)P C a =- ,设平面PBC 的法向量为1(,,)x y z =n ,则110,0PB PC ⋅=⋅=n n,即有 0,20y az y az +-=-=⎪⎩令2z =时,则,3x y a ==.所以1,,2)3a =n ………………8分又因为,D E 分别是,PB PC 的中点,所以1,),(0,1,),222a aD E 则1,),(0,1,).222a aAD AE == 设平面ADE 的法向量为2(,,)x y z =n ,则220,0AD AE ⋅=⋅=n n ,有10,220,2ax y z a y z ++=⎨⎪+=⎪⎩,令2z =时,有,x y a ==-,故2(,,2)a =-n ……………………………………………………………………10分 又因为平面ADE ⊥平面PBC ,所以12120()()220a a ⊥⇔⋅=⇔⨯+⨯-+⨯=n n n n解得a =,即PA =分20.【解】(Ⅰ)从第n 年初到第1n +年初,兔子的繁殖量为n ax ,被捕杀量为n bx ,死亡量为2n cx ,因此2*1,n n n n nx x ax bx cx n N +-=--∈,即*1(1),n n n x x a b cx n N +=+--∈,……………4分 (Ⅱ)当2,1a c ==时,则*1(3),n n n x x b x n N +=--∈,若b 的值使得0n x >,则只需30n b x -->对*n N ∈恒成立,即03n x b <<-,于是令1n =时,必有103x b <<-也成立.而1(0,2)x ∈,于是23b ≤-,即(0,1]b ∈.由此猜想b 的最大允许值是1.……………………………………………………………8分 下面用数学归纳法证明,当1(0,2),1x b ∈=时,都有(0,2)n x ∈ ①当1n =时,结论显然成立;②假设当*(,1)n k k N k =∈≥时,结论成立,即有(0,2)k x ∈,则当1n k =+时,由*1(3),n n n x x b x n N +=--∈得,212(2)()12k k k k k x x x x x ++-=-≤=(当1k x =时取到“=”)所以1(0,1](0,2)k x +∈⊆,即当1n k =+时,结论也成立.综上①②可知对一切*n N ∈,都有(0,2)n x ∈.故捕杀强度b 的最大允许值为1.………………………………………………………13分 21.【解】(Ⅰ)设(,)M x y ,由题可知(0,0)I ,设(0,),(0,2)E t t ∈,(,2)I s ',连结II EJ A ''= ,则,(,1)2s II EJ A ''⊥,又(,2),II s '= (,1)2s E A t =- ,所以22202s t +-=,即244s t =-………3分 又EM EI EI '=+ 得,,2x s y t =⎧⎨=-⎩代入上式得214x y =-+, 又因为点I 都落在边HK 上,故0,2]x s =∈[,即21,024x y x =-+≤≤…………………5分(Ⅱ)依题意曲线D 的方程是22(0)y x x =-≤………………………………………………6分(参考:22222121244424y=x ,x x y x y y y x y x =-+=-=-=-⇔=-沿直线向下平移横坐标伸长为原来个单位的倍纵坐标不变轴翻折 )设200000(,),0,2Q x y x y x <=-,显然直线,QB QC 的斜率都存在,记(0,),(0,),B b C c b c ≠,又设直线00:,y b QB y kx b k x -=+=,1=, 即2210b kb --=,也所以200210y bb b x ---=, 可化为2000(2)20x b y b x +--=. 显然同理可得2000(2)20xc y c x +--=,所以,b c 是2000(2)20x x y x x +--=两根,且200044(2)y x x ∆=++=故00002,22y x b c bc x x -+==++,所以002|||||2|x b c x -=+, 所以20001||||2|2|QBCx S BC x x ∆=⨯=+,又注意到,B C 在原点两侧,故0002x bc x =-<+, 即020x +<,于是20001||||22QBCx S BC x x ∆=⨯=-+,令0(2)m x =-+,则0m >, 于是2(2)44QBC m S m m m∆--==++≥8(当2m =,即04x =-时取到等号).所以QBC ∆面积的最小值为8.…………………………………………………………13分 22.【解】(Ⅰ)21(1)(1)()'x x x xxx xe e ef x e e e e --+-=-==, 显然当(0,)x ∈+∞时,'()0,()f x f x >递增;当(,0)x ∈-∞时,'()f x 所以()f x 在区间[1,ln 2]-上的最大值为(1),(ln 2)f f - 因为1(1)(1)(ln 2)f e f f e -=+=>,所以()f x 在区间[1,ln 2]-上的最大值为1(1)f e e-=+.(Ⅱ)当1a =-时,2(),'()23'x x f x e e g x x -=-=-, 依题意0x R ∃∈,使得00'()'(),f x g x =且00()()f x g x ≠, 令2()'()'()32x x h x f x g x e e x -=-=-+- (结合函数2,32x x y e e y x -=-=-+草图如右)由1(0)20,(1)10h h e e=-<=-+>,所以0(0,1)x ∃∈,使得000()0'()'()h x f x g x =⇔=.又当(0,1)x ∈时,()2x x f x e e -=+≥=,而3()2,(0,1)g x x x x =-+∈,由222'()233()3(3g x x x x x =-=--=-可知,当)x ∈时,'()0g x >,当(3x ∈时,'()0g x <,所以当x =时,()g x 有极大值,也是最大值,此时2()(2))23g x g ≤-<所以当(0,1)x ∈时,()()g x f x <恒成立,即00()()f x g x ≠.所以当1a =-时,0x R ∃∈,使得()y f x =和()y g x =的图象在0x x =处的切线互相平行. (Ⅲ)令2()()()23'x x F x f x g x e e ax -=-=+--,显然()F x 为R 上偶函数,故()'()f x g x ≥恒成立()0F x ⇔≥对[0,)x ∈+∞恒成立. 又因为(0)0F =,可知此时函数min ()0F x =.则又'()()6,0x x F x e e ax x -=--≥,注意到000x x e e e e ---≥-=,所以 ①当0a ≤时,'()0F x ≥,则()F x 在[0,)+∞上递增,符合题意; ②当0a >时,()6"x x F x e e a -=+-,注意到2x x e e -+≥,所以1)当103a <≤时,则"()0,'()F x F x ≥在[0,)+∞上递增,于是'()'(0)0F x F ≥=, 也所以()F x 在[0,)+∞上递增,符合题意;……………………………………………11分2)当13a >时,令"()0F x =的零点为0x t =>,易知函数"()F x 为增函数(其导函数在[0,)+∞上恒大于0),故可知当[0,)x t ∈时,"()0F x <,也所以'()F x 在[0,)t 上递减,故有 ()'(0)0'F x F ≤=,从而()F x 在[0,)t 上递减,于是出现()(0)0F x F <=,这与min ()0F x =矛盾!舍去;综上可知a 的取值范围为1(,]3-∞为所求.………………………………………………13分。
数学理卷·2014届湖南师大附中高三第七次月考试题(2014.03)word版
湖南师大附中2014届高三第七次月考数学(理)试题注意事项: 1.本试题满分150分,考试时间为120分钟. 2.使用答题纸时,必须使用0.5毫米的黑色墨水签字笔书写,作图时,可用2B 铅笔.要字迹工整,笔迹清晰.超出答题区书写的答案无效;在草稿纸,试题卷上答题无效.3.答卷前将密封线内的项目填写清楚.一、选择题:本大题共10小题;每小题5分,共50分.每小题给出四个选项,只有一个选项符合题目要求,把正确选项的代号涂在答题卡上. 1.设集合}032|{2<--=x x x M ,2{|log 0}N x x =<,则N M 等于A .)0,1(-B .)1,1(-C .)1,0(D .)3,1(2.若复数z 的实部为1,且||2z =,则复数z 的虚部是A .B .C . D3. 若命题:p α∃∈R ,cos()cos παα-=;命题:q ∀R ∈x ,012>+x . 则下面结论正确的是A .p 是假命题B .q ⌝是真命题 C .p ∧q 是假命题 D .p ∨q 是真命题4.若函数()21,1ln ,1x x f x x x ⎧+≤=⎨>⎩, 则((e))f f =(其中e 为自然对数的底数)A .0B .1C .2D .2ln(e 1)+5.若一个三棱锥的三视图如图所示,其中三个视图都是直角三角形,则在该三棱锥的四个面中,直角三角形的个数为 A .1 B .2 C .3 D .4 6.在等差数列}{n a 中,12012a =- ,其前n 项和为n S ,若2012102002201210S S -=,则2014S 的值等于 A .2011 B . -2012 C .2014 D . -20137.如图是某班50位学生期中考试数学成绩的频率分布直方图,其中成绩分组区间是:[)4050,,[)5060,,[)6070,,[)7080,,[)8090,,[]90100,,则图中x 的值等于 A .0.12 B .0.18 C .0.0128.函数x x y sin =在[]ππ,-上的图象是9.若函数()2sin()(214)84f x x x ππ=+-<<的图象与x 轴交于点A ,过点A 的直线l 与函数的图象交于B 、C 两点,则=⋅+)((其中O 为坐标原点)A .32-B .32C .72-D .7210. 对任意实数,m n ,定义运算m n am bn cmn *=++,其中c b a ,,为常数,等号右边的运算是通常意义的加、乘运算.现已知12=4*,23=6*,且有一个非零实数t ,使得对任意实数x ,都有x t x *=,则t = A .4 B .5 C .6 D .7二、填空题:本大题共有5个小题,每小题5分,共25分,请将正确答案填在答题卡相应位置. 11.若直线10ax by -+=平分圆22:241C x y x y ++-+0=的周长,则ab 的取值范围是__ 12.若某程序框图如右图所示,则该程序运行后输出的i 值为 。
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湖南师大附中2014届高三第七次月考数学(理)试题注意事项: 1.本试题满分150分,考试时间为120分钟. 2.使用答题纸时,必须使用0.5毫米的黑色墨水签字笔书写,作图时,可用2B 铅笔.要字迹工整,笔迹清晰.超出答题区书写的答案无效;在草稿纸,试题卷上答题无效.3.答卷前将密封线内的项目填写清楚.一、选择题:本大题共10小题;每小题5分,共50分.每小题给出四个选项,只有一个选项符合题目要求,把正确选项的代号涂在答题卡上. 1.设集合}032|{2<--=x x x M ,2{|log 0}N x x =<,则N M 等于A .)0,1(-B .)1,1(-C .)1,0(D .)3,1(2.若复数z 的实部为1,且||2z =,则复数z 的虚部是A .B .C . D3. 若命题:p α∃∈R ,cos()cos παα-=;命题:q ∀R ∈x ,012>+x . 则下面结论正确的是A .p 是假命题B .q ⌝是真命题 C .p ∧q 是假命题 D .p ∨q 是真命题4.若函数()21,1ln ,1x x f x x x ⎧+≤=⎨>⎩, 则((e))f f =(其中e 为自然对数的底数) A .0 B .1C .2D .2ln(e 1)+5.若一个三棱锥的三视图如图所示,其中三个视图都是直角三角形,则在该三棱锥的四个面中,直角三角形的个数为 A .1 B .2 C .3 D .4 6.在等差数列}{n a 中,12012a =- ,其前n 项和为n S ,若2012102002201210S S -=,则2014S 的值等于 A .2011 B . -2012 C .2014 D . -20137.如图是某班50位学生期中考试数学成绩的频率分布直方图, 其中成绩分组区间是:[)4050,,[)5060,,[)6070,, [)7080,,[)8090,,[]90100,,则图中x 的值等于 A .0.12 B .0.18 C .0.0120.0188.函数x x y sin =在[]ππ,-上的图象是9.若函数()2sin()(214)84f x x x ππ=+-<<的图象与x 轴交于点A ,过点A 的直线l 与函数的图象交于B 、C 两点,则=⋅+)((其中O 为坐标原点)A .32-B .32C .72-D .7210. 对任意实数,m n ,定义运算m n am bn cmn *=++,其中c b a ,,为常数,等号右边的运算是通常意义的加、乘运算.现已知12=4*,23=6*,且有一个非零实数t ,使得对任意实数x ,都有x t x *=,则t = A .4 B .5 C .6 D .7二、填空题:本大题共有5个小题,每小题5分,共25分,请将正确答案填在答题卡相应位置. 11.若直线10ax by -+=平分圆22:241C x y x y ++-+0=的周长,则ab 的取值范围是12.若某程序框图如右图所示,则该程序运行后输出的i 值为 。
13. 已知变量y x ,满足约束条件⎪⎩⎪⎨⎧≥+-≥≤+-042042k y x y y x ,且目标函数y x z +=3的最小值为1-,则实常数=k 。
14. 对大于或等于2的正整数的幂运算有如下分解方式: 。
3122+= 53132++= 753142+++= … 5323+= 119733++= 1917151343+++= …频率x根据上述分解规律,若115312++++= m ,3p 的分解中最小的正整数是21,则=+p m 。
15.已知抛物线24y x =的准线与双曲线22221x y a b-=的两条渐近线分别交于A ,B两点,且||AB =,则双曲线的离心率e 为 。
三、解答题.本大题共6个小题,共75分.解答时要求写出必要的文字说明、证明过程或推理步骤. 16.(本小题满分12分)全国第十二届全国人民代表大会第二次会议和政协第十二届全国委员会第二次会议,2014年3月在北京开幕.期间为了了解国企员工的工资收入状况,从108名相关人员中用分层抽样方法(1)求x ,y ; (2)若从中层、高管抽取的人员中选2人,求这二人都自中层的概率. 17.(本小题满分12分)已知函数27()sin 22sin 1()6f x x x x π⎛⎫=--+∈⎪⎝⎭R , (1)求函数()f x 的周期及单调递增区间;(2)在ABC ∆中,三内角A ,B ,C 的对边分别为c b a ,,,已知函数()f x 的图象经过点1,,,,2A b a c ⎛⎫⎪⎝⎭成等差数列,且9AB AC ⋅=,求a 的值. 18.(本小题满分12分)如图1,在直角梯形ABCD 中,//AD BC ,90,ADC BA BC ∠==.把BAC ∆沿AC 折起到PAC ∆的位置,使得P 点在平面ADC 上的正投影O 恰好落在线段AC 上,如图2所示,点E F 、分别为棱PC CD 、的中点. (1)求证:平面//OEF 平面APD ; (2)求证:CD ⊥平面POF ;(3)若3,4,5AD CD AB ===,求四棱锥E CFO -的体积.19.(本小题满分12分) 已知数列{}n a 的前n 项和为n S ,且22n n S a +=,数列{}n b 满足11b =,且12n n b b +=+.(1)求数列{}n a ,{}n b 的通项公式;(2)设1(1)1(1)22n nn n n c a b --+-=-,求数列{}n c 的前2n 项和2n T .20.(本小题满分13分) 已知函数+1()ln +1a f x x ax x=+-. (1)当1a =时,求曲线()y f x =在点(2,(2))f 处的切线方程;(2)当102a -≤≤时,讨论()f x 的单调性.21. (本小题满分14分)已知椭圆)0(1:2222>>=+b a by a x C 经过点(1,)2P ,且两焦点与短轴的两个端点的连线构成一正方形.(1)求椭圆C 的方程;(2)直线l 与椭圆C 交于A ,B 两点,若线段AB 的垂直平分线经过点1(0,)2-,求AOB ∆(O 为原点)面积的最大值.参考答案一、选择题C BD C D C D A D B 二、填空题11.1(,]8-∞ 12. 8 13. 9 14. 11 15.2 三、解答题16.解:(1)由题意可得2632718x y ==,所以7x =,3y =. ……………………3分 (2)记从中层抽取的3人为1b ,2b ,3b ,从高管抽取的2人为1c ,2c ,则抽取的5人中选2人的基本事件有:12(,)b b ,13(,)b b ,11(,)b c ,12(,)b c ,23(,)b b ,21(,)b c ,22(,)b c ,31(,)b c ,32(,)b c ,12(,)c c 共10种. ……8分设选中的2人都自中层的事件为A ,则A 包含的基本事件有:12(,)b b ,13(,)b b ,23(,)b b 共3种. ………………10分因此3()0.310P A ==. 故选中的2人都自中层的概率为0.3. ……………………………………12分17.解:2711()sin(2)2sin 1cos 22cos 2cos 22622f x x x x x x x x π=--+=-+=+s i n (2)6x π=+………………………………………………3分(1)最小正周期:22T ππ==, ………………………………………………4分 由222()262k x k k Z πππππ-≤+≤+∈可解得:()36k x k k Z ππππ-≤≤+∈,所以()f x 的单调递增区间为:[,]()36k k k Z ππππ-+∈; ………………6分 (2)由1()sin(2)62f A A π=+=可得:5222()666A k k k Z πππππ+=++∈或所以3A π=, ………………………………………………8分又因为,,b a c 成等差数列,所以2a b c =+, ………………9分而1cos 9,182AB AC bc A bc bc ⋅===∴= ………………………………10分 222221()4cos 111223612b c a a a a A bc +--∴==-=-=-,a ∴= ………………………………………………12分18.解:(1)因为点P 在平面ADC 上的正投影O 恰好落在线段AC 上所以PO ⊥平面ABC ,所以PO ⊥AC …………………1分 因为AB BC =,所以O 是AC 中点, …………………2分 所以//OE PA ,PA PAD ⊂平面所以 //OE PAD 平面 …………………3分 同理//OF PAD 平面 又,OEOF O OE OF OEF =⊂、平面所以平面//OEF 平面PDA …………………5分 (2)因为//OF AD ,AD CD ⊥所以OF CD ⊥ 又PO ⊥平面ADC ,CD ⊂平面ADC所以PO ⊥CD …………………7分 又OF PO O =所以CD ⊥平面POF …………………8分 (3)因为90ADC ∠=,3,4AD CD ==,所以13462ACD S ∆=⨯⨯=,而点,O E 分别是,AC CD 的中点,所以1342CFO ACD S S ∆∆==, …………………10分由题意可知ACP ∆为边长为5的等边三角形,所以高OP = …………11分即P 点到平面ACD E 为PC 的中点,所以E 到平面CFO 1332E CFO V -=⨯=. …………………12分19.解:(1)当1=n ,21=a ; ………………………1分 当2≥n 时,1122n n n n n a S S a a --=-=- ,∴ 12n n a a -=. ……………2分∴{}n a 是等比数列,公比为2,首项12a =, ∴2nn a =. ………3分由12n n b b +=+,得{}n b 是等差数列,公差为2. ……………………4分又首项11=b ,∴ 21n b n =-. ……………………………6分(2)2(21)n n c n ⎧=⎨--⎩为偶数为奇数n n ……………………8分3212222[37(41)]n n T n -=+++-+++- ……………10分2122223n n n +-=--. ……………………………12分20.解:(1)当1a =时,2()ln +1f x x x x=+-, 此时'212()+1f x x x =-, ………………………………2分 '12(2)+1124f =-=,又2(2)ln 2+21ln 2+22f =+-=,所以切线方程为:(ln2+2)2y x -=-,整理得:ln20x y -+=; …………………………5分(2)2'222111(1)(1)()a ax x a ax a x f x a x x x x++--++-=+-==, ……6分 当0a =时,'21()x f x x-=,此时,在'(0,1)()0f x <,()f x 单调递减, 在'(1,)()0f x +∞>,()f x 单调递增; …………………………… 8分当102a -≤<时,'21()(1)()aa x x a f x x ++-=, 当11a a +-=即12a =-时2'2(1)()02x f x x -=-≤在(0,)+∞恒成立, 所以()f x 在(0,)+∞单调递减; …………………………………10分 当102a -<<时,11a a +->,此时在'1(0,1),(,)()0af x a +-+∞<,()f x 单调递减,()f x 在'1(1,)()0a f x a->单调递增; ………………………………12分综上所述:当0a =时,()f x 在(0,1)单调递减,()f x 在(1,)+∞单调递增;当102a -<<时, ()f x 在1(0,1),(,)a a -+∞单调递减,()f x 在1(1,)a a-单调递增; 当12a =-时()f x 在(0,)+∞单调递减. ……………………………………13分21.解 (1)∵椭圆)0(1:2222>>=+b a by a x C 的两焦点与短轴的两个端点的连线构成正方形,∴a =, ∴222212x y b b+=, …………2分又∵椭圆经过点(1,2P ,代入可得21b =,∴故所求椭圆方程为22 1.2x y += …………4分 (2)设1122(,),(,),A x y B x y 因为AB 的垂直平分线通过点1(0,)2-, 显然直线AB 有斜率, 当直线AB 的斜率为0时,则AB 的垂直平分线为y 轴,此时1212,x x y y =-=所以11111=|2|||||||2AOB S x y x y ∆=,因为221112x y +=,所以2211111||||||)222x x y y y =≤+=所以AOB S ∆≤,当且仅当1||1x =时,AOB S ∆取得最大值为, ……………7分当直线AB 的斜率不为0时,则设AB 的方程为y kx t =+所以2212y kx t x y =+⎧⎪⎨+=⎪⎩,代入得到222(21)4220k x ktx t +++-= ……………8分 当228(21)0k t ∆=-+>, 即2221k t +> ① 方程有两个不同的解又122421ktx x k -+=+,1222221x x kt k +-=+ ………………10分所以122221y y tk+=+,又121211222y yx x k++=-+-,化简得到2212k t+=②代入①,得到02t<<…………………11分又原点到直线的距离为d=12|||AB x x-=所以1=||||2AOBS AB d∆=考虑到2212k t+=且02t<<化简得到AOBS∆…………………13分因为02t<<,所以当1t=时,即k=时,AOBS∆取得最大值.综上,AOB∆面积的最大值为.…………………14分。