2021届江苏省G4(苏州中学、盐城中学、扬州中学等)高三上学期1月期末调研考试理综生物试卷及解析
江苏省扬州中学2022-2023学年高三上学期1月月考(期末)数学试题 附答案
江苏省扬州中学2022-2023学年度1月月考试题 高三数学 2023.01试卷满分:150分, 考试时间:120分钟一、单项选择题:本大题共8小题,每小题5分,共40分.在每题给出的四个选项中,只有一项是最符合题意的.(请将所有选择题答案填到答题卡的指定位置中.)1.已知复数3i z =(i 为虚数单位),则22z z-的共轭复数的模是( )A .1B .3C .5D .72.已知集合(){}{}ln 12,Z 3sin A x x B y y x =+<=∈=,则A B =( )A .{}0,1,2,3B .{}0,3C .{}3D .∅3.设123,,a a a ∈R ,则“123,,a a a 成等比数列”是“()()()2222212231223a a a a a a a a ++=+”的( )A .充分而不必要条件B .必要而不充分条件C .充要条件D .既不充分也不必要条件4.某中学全体学生参加了数学竞赛,随机抽取了400名学生进行成绩统计,发现抽取的学生的成绩都在50分至100分之间,进行适当分组后(每组为左闭右开的区间),画出频率分布直方图如图所示,每组数据以组中值(组中值=(区间上限+区间下限)/2)计算),下列说法正确的是( )A .直方图中x 的值为0.035B .在被抽取的学生中,成绩在区间[)70,80的学生数为30人C .估计全校学生的平均成绩为83分D .估计全校学生成绩的样本数据的80%分位数约为95分5.已知π0,2α⎛⎫∈ ⎪⎝⎭,且tan 32πcos 4αα⎛⎫+= ⎪⎝⎭,则sin 2α=( )A .13- B .16 C .13 D .236.在平面直角坐标系xOv 中,M 为双曲线224x y -=右支上的一个动点,若点M 到直线20x y -+=的距离大于m 恒成立,则实数m 的最大值为( )A. 1B. 2C. 2D. 227.如图是一个由三根细棒PA 、PB 、PC 组成的支架,三根细棒PA 、PB 、PC 两两所成的角都为60︒,一个半径为1的小球放在支架上,则球心O 到点P 的距离是( )A .32 B .2 C .3 D .28.已知函数()f x 及其导函数()f x '的定义域均为R ,且()52f x +是偶函数,记()()g x f x '=,()1g x +也是偶函数,则()2022f '的值为( )A .-2B .-1C .0D .2二、多项选择题:本大题共4小题,每小题5分,共20分.在每题给出的四个选项中,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.(请将所有选择题答案填到答题卡的指定位置中.) 9.如图,在正方体1111ABCD A B C D -中,E 为1AA 的中点,则( ) A .11//A D 平面BEC B .1AB ⊥平面BECC .平面11AA B B ⊥平面BECD .直线1DD 与平面BEC 所成角的余弦值为5510.已知函数()()2πsin 02f x x ϕϕ⎛⎫=+<< ⎪⎝⎭的一条对称轴为π3x =,则( )A .()f x 的最小正周期为πB .()104f =C .()f x 在π2π,33⎛⎫⎪⎝⎭上单调递增 D .π6x f x ⎛⎫≥- ⎪⎝⎭11.已知数列{}n a 中,12a =,()21212n n a a +=++-,则关于数列{}n a 的说法正确的是( )A .25a =B .数列{}n a 为递增数列C .221n a n n =+- D .数列11n a ⎧⎫⎨⎬+⎩⎭的前n 项和小于3412.已知函数()sin f x x =,()()0g x kx k =>,若()f x 与()g x 图象的公共点个数为n ,且这些公共点的横坐标从小到大依次为1x ,2x ,…,n x ,则下列说法正确的有( )A .若1n =,则1k >B .若3n =,则33321sin 2x x x =+ C .若4n =,则1423x x x x +<+ D .若22023k π=,则2024n =三、填空题:本大题共4小题,每小题5分,共20分.(请将所有填空题答案填到答题卡的指定位置中.)13.已知52212x ax ⎛⎫+ ⎪⎝⎭展开式中的各项系数和为243,则其展开式中含2x 项的系数为_____.14.已知()()2,1,3,a b a b a ==--⊥,则a 与b 的夹角为__________.15.已知()()12,0,,0F c F c -为椭圆2222:1x y C a b+=的两个焦点,P 为椭圆C 上一点(P 不在y轴上),12PF F △的重心为G ,内心为M ,且12//GM F F ,则椭圆C 的离心率为___________.16.对于函数()f x 和()g x ,设{|()0}x f x α∈=,{|()0}x g x β∈=,若存在α、β,使得||1αβ-<,则称()f x 与()g x 互为“零点相邻函数”.若函数1()e 2-=+-x f x x 与2()3g x x ax a =--+互为“零点相邻函数”,则实数a 的取值范围为______.四、解答题:本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.(请将所有解答题答案填到答题卡的指定位置中.)17.已知数列{}n a 满足,12(1)nn n a a +=+⋅-.(1)若11a =,数列{}2n a 的通项公式; (2)若数列{}n a 为等比数列,求1a .18.记锐角ABC 的内角A ,B ,C 的对边分别为a ,b ,c ,sin sin tan cos cos A CB A C+=+.(1)求B ;(2)求()2a c ab -的取值范围.19.密室逃脱可以因不同的设计思路衍生出不同的主题,从古墓科考到蛮荒探险,从窃取密电到逃脱监笼,玩家可以选择自己喜好的主题场景在规定时间内完成任务,获取奖励.李华参加了一次密室逃脱游戏,他选择了其中一种模式,该游戏共有三关,分别记为A ,B ,C ,他们通过三关的概率依次为:211,,323.若其中某一关不通过,则游戏停止,游戏不通过.只有依次通过A ,B ,C 三道关卡才能顺利通关整个游戏,并拿到最终奖励.现已知参加一次游戏的报名费为150元,最终奖励为400元.为了吸引更多的玩家来挑战该游戏,商家推出了一项补救活动,可以在闯关前付费购买通关币.游戏中,若某关卡不通过,则自动使用一枚通关币通过该关卡进入下一关.购买一枚通关币需另付100元,游戏结束后,剩余的未使用的通关币半价回收.(1)若李华同学购买了一枚通关币,求他通过该游戏的概率. (2)若李华同学购买了两枚通关币,求他最终获得的收益期望值.(收益等于所得奖励减去报名费与购买通关币所需费用).20.图1是直角梯形ABCD ,AB CD ,90D ∠=,2AB =,3DC =,3AD =,2CE ED =,以BE 为折痕将BCE 折起,使点C 到达1C 的位置,且16AC =,如图2. (1)求点D 到平面1BC E 的距离;(2)若113DP DC =,求二面角P BE A --的大小.21.已知点()1,2Q 是焦点为F 的抛物线C :()220y px p =>上一点. (1)求抛物线C 的方程;(2)设点P 是该抛物线上一动点,点M ,N 是该抛物线准线上两个不同的点,且PMN 的内切圆方程为221x y +=,求PMN 面积的最小值.22.已知函数()ln f x x ax a =-+,其中R a ∈. (1)讨论函数()f x 的单调性;(2)若()f x 在(]0,1上的最大值为0, ①求a 的取值范围;①若2()31f x kx ax ≤-+恒成立,求正整数k 的最小值.参考答案: 1.C 【详解】因为3i i z ==-,所以22212i 112i i z z -=+=+=+-,所以22z z -的共轭复数为12i -,12i 5-=,所以22z z-52.A 【详解】由()ln 12x +<,可得201e x <+<,则{}21e 1A x x =-<<-∣ 又{}{}Z 3sin 3,2,1,0,1,2,3B y y x =∈==---,所以{}0,1,2,3A B =.3.A 【详解】①若123,,a a a 成等比数列,则2213a a a =⋅,所以()()22221223a a a a ++()()22113133a a a a a a =+⋅⋅+()()113133a a a a a a ⎡⎤⎡⎤=++⎣⎦⎣⎦()21313a a a a =+()22132a a a =+()2132a a a ⎡⎤=+⎣⎦()21223a a a a =+;①若1230a a a ===,满足()()()2222212231223a a a a a a a a ++=+,但是不满足123,,a a a 成等比数列(因为等比数列中不能含有0)“123,,a a a 成等比数列”是“()()()2222212231223a a a a a a a a ++=+”的充分不必要条件, 4.D 【详解】对于A :根据学生的成绩都在50分到100分之间的频率和为1,可得10⨯(0.005+0.01+0.015+x +0.040)=1,解得x =0.03,故A 错误;对于B :在被抽取的学生中,成绩在区间[)70,80的学生数为10⨯0.015⨯400=60人, 故B 错误;对于C :估计全校学生的平均成绩为55⨯0.05+65⨯0.1+75⨯0.15+85⨯0.3+95⨯0.4=84分; 故C 错误.对于D :全校学生成绩的样本数据的80%分位数约为0.29010950.4+⨯=分. 故D 正确.5.D 【详解】设π4αβ+=,π3π,44β⎛⎫∈ ⎪⎝⎭,则π4αβ=-,tan 32πcos 4αα⎛⎫+= ⎪⎝⎭, 即πtan 3cos 23sin 22βββ⎛⎫=-= ⎪⎝⎭,sin 6sin cos cos ββββ=,sin 0β≠, 故21cos 6β=,22sin 2sin 2cos 212cos 23παβββ⎛⎫=-=-=-= ⎪⎝⎭.6.B 【详解】由点M 到直线20x y -+=的距离大于m 恒成立,可得点M 到直线20x y -+=的最近距离大于m .因为双曲线的渐近线为y x =,则y x =与20x y -+=的距离222d ==即为最近距离,则2m ≤,即max 2m =.7.C 【详解】如图所示,连接,,AB AC BC ,作ABC 所在外接圆圆心1O ,连接1,AO AO ,设PA x =,由PA 、PB 、PC 两两所成的角都为60︒可得AB AC BC x ===,因为1O 为ABC 几何中心,所以132332333AO AB AB x =⋅⋅==,易知对1PAO △和POA ,1,90P P PO A PAO ∠=∠∠=∠=︒,所以1PAO POA △≌△,所以1PA PO AO AO =,即133xPOx =,解得3PO =.故选:C8.C 【详解】因为()52f x +是偶函数,所以(52)(52)f x f x -+=+ ,两边求导得5(52)5(52)f x f x ''--+=+ ,即(52)(52)f x f x ''--+=+,所以(52(52)g x g x +=--+),即()(4)g x g x =--+, 令2x = 可得(2)(2)g g =- ,即(2)0=g , 因为()1g x +为偶函数,所以(1)(1)g x g x +=-+ ,即()(2)g x g x =-+ , 所以(4)(2)g x g x --+=-+ ,即()(2)g x g x =-+ ,(4)(2)()g x g x g x ∴+=-+= ,所以4是函数()g x 的一个周期, 所以(2022)(2022)(50542)(2)0f g g g '==⨯+==, 9.ACD10.ABD 【详解】因为函数21cos(22)11()sin ()cos(22)222x f x x x ϕϕϕ-+=+==-++, 因为函数()()2πsin 02f x x ϕϕ⎛⎫=+<< ⎪⎝⎭的一条对称轴为3x π=,所以π22π,()3k k ϕ⨯+=∈Z ,解得:ππ,()23k k ϕ=-∈Z , 又因为π02ϕ<<,所以π1,6k ϕ==,则1π1()cos(2)232f x x =-++,对于A ,函数()f x 的最小正周期πT =,故选项A 正确;对于B ,1111(0)2224f =-⨯+=,故选项B 正确;对于C ,因为π2π33x <<,所以π5ππ<2+33x <,因为函数cos y t =-在5π(π,)3上单调递减,故选项C 错误;对于D ,因为π11()cos 2622f x x -=-+,令π11()()cos 2622g x x f x x x =--=+-,当0x ≥时,11()cos 222g x x x =+-,则()1sin 20g x x ='-≥,所以()g x 在[0,)+∞上单调递增,则()(0)0g x g ≥=,也即π()6x f x ≥-,当0x <时,11()cos 222g x x x =-+-,则()1sin 20g x x ='--≤,所以()g x 在(,0)-∞上单调递减,则()(0)0g x g ≥=,也即π()6x f x -≥-,综上可知:6x f x π⎛⎫≥- ⎪⎝⎭恒成立,故选项D 正确,11.BCD 【详解】由)21212n n a a +=+-,得()21221n n a a ++=+1221n n a a +++,又12a =122a +所以{}2n a +是以2为首项,1为公差的等差数列,22(1)11n a n n ++-⨯=+,即221n a n n =+-, 所以27a =,故A 错误,C 正确;()212n a n =+-,所以{}n a 为递增数列,故B 正确;()211111112222n a n n n n n n ⎛⎫===- ⎪++++⎝⎭, 所以数列11n a ⎧⎫⎨⎬+⎩⎭的前n 项和为11111111111...232435112n n n n ⎛⎫-+-+-++-+- ⎪-++⎝⎭ 1111311131221242124n n n n ⎛⎫⎛⎫=+--=-+< ⎪ ⎪++++⎝⎭⎝⎭,故D 正确. 12.BCD 【详解】对于A :当1k =时,令sin y x x =-,则cos 10y x =-≤,即函数sin y x x =-有且仅有一个零点为0,同理易知函数sin y x x =--有且仅有一个零点为0,即()f x 与()g x 也恰有一个公共点,故A 错误; 对于B :当3n =时,如下图:易知在3x x =,且()3,2x ππ∈,()f x 与()g x 图象相切,由当(),2x ∈ππ时,()sin f x x =-,则()cos f x x '=-,()g x k '=,故333cos sin k x x kx =-⎧⎨-=⎩,从而33tan x x =,所以()222333332333333cos 1tan 1tan 112tan tan tan cos tan sin 2x x x x x x x x x x x +++=+===,故B 正确; 对于C :当4n =时,如下图:则10x =,42x ππ<<,所以142x x π+<,又()f x 图象关于x π=对称,结合图象有32x x ππ->-,即有32142x x x x π+>>+,故C 正确;对于D :当22023k π=时,由20232023()122f g ππ⎛⎫== ⎪⎝⎭,()f x 与()g x 的图象在y 轴右侧的前1012个周期中,每个周期均有2个公共点,共有2024个公共点,故D 正确.13.80 14. π415.12【详解】设()()000,0P x y x ≠,由于G 是12PF F △的重心,由重心坐标公式可得00,33x y G ⎛⎫⎪⎝⎭,由于12//GM F F ,所以M 的纵坐标为03M y y =,由于M 是12PF F △的内心,所以12PF F △内切圆的半径为03y r =,由椭圆定义得12212,2PF PF a F F c +==, ()2121210120122111223PF F MF F MF P MPF y SSSSF F y F F PF F P =++⇒⋅=++, ()001222232y c y a c a c e =+⇒=⇒= 16.23a ≤<【详解】因为(1)0f =,且函数1()e 2-=+-x f x x 为单调递增函数,所以1为函数1()e 2-=+-x f x x 的唯一零点, 设函数2()3g x x ax a =--+的零点为b ,又因为函数1()e 2-=+-x f x x 与2()3g x x ax a =--+互为“零点相邻函数”, 所以|1|1b -<,解得02b <<,所以函数2()3g x x ax a =--+在(0,2)上有零点,所以(0)(2)0g g ⋅<或()2022Δ430a a a ⎧<<⎪⎨⎪=--+=⎩或()()()2022Δ4300020a a a g g ⎧<<⎪⎪⎪=--+>⎨⎪>⎪>⎪⎩, 即733a <<或2a =或23a <<,所以23a ≤<. 17.【详解】(1)由题意得()121nn n a a +-=⋅-,所以()()()22212122211n n n n n a a a a a a a a ---=-+-++-+()()()212212121211n n --=⋅-+⋅-++⨯-+211=-+=-.(2)设数列{}n a 的公比为q ,因为()121n n n a a +=+⋅-,所以212a a =-,322a a =+,两式相加得2311a a q a =⋅=,所以1q =±,当1q =时,2112a a a ==-不成立,所以1q =-,2112a a a =-=-,解得11a =.18.【详解】(1)因为sin sin tan cos cos A C B A C +=+,即sin sin sin cos cos cos B A CB A C+=+,所以sin cos sin cos cos sin cos sin B A B C B A B C +=+,即sin cos cos sin cos sin sin cos B A B A B C B C -=-,所以sin()sin()B A C B -=-,因为0πA <<,0πB <<,所以ππB A -<-<,同理得ππC B -<-<, 所以B A C B -=-或()()πB A C B -+-=±(不成立), 所以2B A C =+,结合πA B C ++=得π3B =.(2)由余弦定理2221cos 22a c b B ac+-==得,222ac a c b =+-,所以222ac a c b -=-,则2222222()1a c a ac a c b c b b b b ---⎛⎫===- ⎪⎝⎭, 由正弦定理得,sin 23sin sin 3cC C bB ==, 因为π3B =,2π3A C +=,π02A <<,π02C <<,所以ππ62C <<,1sin 12C <<,所以32333c b ⎛⎫∈ ⎪ ⎪⎝⎭,,2()2133a c a b -⎛⎫∈- ⎪⎝⎭,. 19.【详解】(1)由题意可知:这一枚通关币的使用情况有四种: ①在第一关使用;①在第二关使用;①在第三关使用;①没有使用.而通过三关的概率依次为:211,,323,则李华通过该游戏的概率11121121221113233233233232P =⨯⨯+⨯⨯+⨯⨯+⨯⨯=.(2)购买两枚通关币的费用为200元,报名费为150元,则收益可能为:1400(150200100)150x =-+-=(未使用通关币过关), 2400(15020050)100x =-+-=(使用1枚通关币且过关), 3400(15020050)x =-+=(使用2枚通关币且过关), 4(150200350)x =-+=-(使用2枚通关币且未过关),则12111(150)3239p x ==⨯⨯=2117(100)2918p x ==-=31111122127(50)32332332318p x ==⨯⨯+⨯⨯+⨯⨯=41121(350)3239p x =-=⨯⨯=则17()150100918E x =⨯+⨯13255035018997+⨯-⨯=. 所以他最终获得的收益期望值是3259元.20【详解】(1)解:如图所示: 连接AC ,交BE 于F ,因为90D ∠=,2AB =,3DC =,3AD =,2CE ED =,所以AE =2,又AB CD ,所以四边形ABCE 是菱形, 所以AC BE ⊥,在ACD 中,2223AC AD CD =+=,所以3AF CF ==,又16AC =,则2221AC AF CF =+, 所以1C F AF ⊥,又AF BE F ⋂=, 所以1C F ⊥平面ABED ,设点D 到平面1BC E 的距离为h ,因为1113233,13222C BE DBESS =⨯⨯==⨯⨯=,且11C DBE D C BE V V --=, 所以111133C BE DBE h S C F S ⨯⨯=⨯⨯,解得32h =;(2)由(1)建立如图所示空间直角坐标系:则()()()()133,,0,0,0,3,0,1,0,0,1,0,3,0,022D C B E A ⎛⎫-- ⎪ ⎪⎝⎭, 所以()()3,1,0,0,2,0BA BE =-=-,因为113DP DC =,所以133,2,3133BP BD BD DP DC ⎛⎫=++=- ⎪ ⎪=⎝⎭, 设平面BEP 的一个法向量为(),,m x y z =, 则00m BE m BP ⎧⋅=⎪⎨⋅=⎪⎩,即20332033y x y z -=⎧⎪⎨-+=⎪⎩, 令1x =,得()1,0,1m =-,易知平面BEA 的一个法向量为()0,0,1n =, 所以2cos ,2m n m n m n⋅==-⋅,则3,4m n π=, 易知二面角P BE A --的平面角是锐角, 所以二面角P BE A --的大小为4π. 21.【详解】(1)因为点()1,2Q 是抛物线C :()220y px p =>上一点, 所以42p =,解得:2p =, 所以24y x =.(2)设点()00,P x y ,点()1,M m -,点()1,N n -,直线PM 方程为:()0011y my m x x --=++,化简得()()()()0000110y m x x y y m m x --++-++=.PMN 的内切圆方程为221x y +=,∴圆心()0,0到直线PM 的距离为1,即()()()002200111y m m x y m x -++=-++.故()()()()()()222220000001211y m x y m m y m x m x -++=-+-+++.易知01x >,上式化简得,()()20001210x m y m x -+-+=.同理有()()20001210x n y n x -+-+=,∴m ,n 是关于t 的方程()()20001210x t y t x -+-+=的两根.∴0021y m n x -+=-,()0011x mn x -+=-.∴()()()()222200200414411x y MN m n m n mnx x +=-=+-=+--.2004y x =,∴()20000220004116412(1)1(1)x x x x MN x x x ++-=+---点(00,P x y 到直线=1x -的距离为01d x =+,所以PMN 面积为()())()()()22200000022004114111212211xx x x x S MN d xx x +-++-=⋅=⨯+=-- 令()010x t t -=>,则()()22222444640161032tt t tS t t t t t++++==++++ 因为2222161628t t t t +≥⋅,4040101040t t t t+≥⋅=, 当且仅当2t =取等,所以840325S ≥++= 故PMN 面积的最小值为4522.【详解】(1)()'1f x a x =- ,若0a ≤ ,则有()'0f x > ,()f x 单调递增;若0a > ,()'11a x a f x a x x⎛⎫- ⎪⎝⎭=-= ,当10x a<< 时,()'0f x > ,()f x 单调递增, 当1x a > 时,()'0f x < ,()f x 单调递减;(2)①由(1)的讨论可知,当0a ≤ 时,()f x 单调递增,在(]0,1x ∈ ,()()max 10f x f == ,满足题意; 当11a≥ 时,在(]0,1x ∈ ,()()max 10f x f ==,满足题意; 当101a << 时,即1a >,在(]0,1x ∈,()max 11ln 1ln 1f x f a a a a a ⎛⎫==-+=-- ⎪⎝⎭, 令()ln 1g x x x =-- ,则()'111x g x x x-=-= ,当1x >时,()'g x >0 ,()g x 单调递增, ()()10g x g ∴=> ,即ln 10a a --> ,不满足题意; 综上,a 的取值范围是1a ≤ ;①由题意,1k ≥ ,2ln 31x ax a kx ax -+≤-+ ,即()2ln 121kx x a x -+≥+ ,考虑直线()21y a x =+ 的极端情况a =1,则2ln 2kx x x ≥+ ,即2ln 2x x k x +≥ ,令()2ln 2x x h x x += ,()'3122ln x x h x x --= ,显然()122ln k x x x =-- 是减函数, 333222471033e e e k ⎛⎫== ,44302e e k = ,①存在唯一的0432e ex ⎛⎫∈ 使得()'00h x = ,当0x x > 时,()'h x <0 ,当0x x < 时,()'h x >0 ,00122ln 0x x --= ,()()002max 012x h x h x x +== ,()max 432e e h h x h ⎛⎫∴<< , 即()max 24h x << ,故k 的最小值可能是3或4,验算23ln 20x x x --≥ , 由于ln 1≤-x x ,223ln 2331x x x x x ∴--≥-+ ,23340∆=-⨯< , 223ln 23310x x x x x ∴--≥-+> ,满足题意; 综上,a 的取值范围是1a ≤ ,k 的最小值是3.。
2021年江苏省扬州中学高三生物上学期期末考试试卷及答案解析
2021年江苏省扬州中学高三生物上学期期末考试试卷及答案解析一、选择题:本题共15小题,每小题2分,共30分。
每小题只有一个选项符合题目要求。
1. 如图为突触结构模式图,a、d分别表示两个神经元的局部。
下列与此相关的表述中正确的是()A.在a中可发生电信号→化学信号→电信号的转变B.③内的递质只能经③释放再作用于③C.兴奋由b传至c的过程中,③处膜外电流方向是b→cD.经③释放的递质必然引起神经元d的兴奋2. 如图是两种细胞的亚显微结构示意图。
以下叙述正确的是()A. 与甲细胞相比,乙细胞特有的细胞器有③③③B. 甲细胞中参与抗体合成和分泌的具膜细胞器有③③③③C. 可以利用差速离心法将图示各种细胞器分离开D. 乙图中结构③的膜蛋白合成加工与③③③③无关3. 神经系统是机体内对生理功能活动的调节起主导作用的系统,主要由神经组织组成,分为中枢神经系统和周围神经系统两大部分。
下列有叙述正确的是()A. 位于下丘脑的呼吸中枢是维持生命的必要中枢B. 中枢神经系统是由大脑和脊髓组成的C. 高级中枢和低级中枢对身体运动都有调节作用D. 脑神经和脊髓是神经系统的周围部分4. 用盐腌制的蔬菜可以保存较长时间而不腐败变质,这可能是因为()A. 蔬菜细胞渗透失水过多而死亡,不能为微生物生长繁殖提供足够营养B. 蔬菜细胞吸收盐分过多而死亡,不能为微生物生长繁殖提供足够营养C. 微生物细胞渗透失水过多,难以生长繁殖D. 微生物细胞吸收盐分过多,难以生长繁殖5. 蚜虫是一种能进行光合作用的昆虫,其体内能合成类胡萝卜素吸收光能,再将能量传送给相关的组织细胞以制造有机物。
下列说法正确的是()A.类胡萝卜素主要吸收蓝紫光,可用无水乙醇提取并分离B.影响蚜虫体内ATP合成速率的外部因素有光照强度、温度、氧浓度等C.蚜虫有氧呼吸终产物H2O中的氢均来自细胞中的葡萄糖D.蚜虫体内ATP含量白天相对夜间会显著增加6. 下列关于糖类和脂质的叙述,正确的是()A.小麦细胞中含有丰富的多糖,如淀粉、麦芽糖B.等量的脂肪和糖类,脂肪所含的能量多C.糖类是细胞内良好的储能物质D.脂质在充足的情况下,可大量转化为糖类7. 如图表示果蝇精原细胞在分裂过程中细胞内染色体数目、核DNA分子含量等指标的变化情况,其中图1中的乙曲线表示减数分裂过程中的染色体数目变化。
1月江苏省扬州市第一中学2021-2021学年度第一学期高三期末试题
度第一学期高三期末试题一、填空题(每小题5分,共70分)1.α是第一象限角,43tan =α,则=αsin ____________2.已知复数z=3-4i,则复数z 的实部和虚部之和为_____________3.已知集合A ={-1,3,m},集合B ={3,4}。
若B ⊆A ,则实数m =___________ 4. 程序如下:1←t 2←iWhile 4≤ii t t ⨯← 1+←i i End While int Pr t以上程序输出的结果是5.在平面直角坐标系xOy 中,直线(1)2x m y m ++=-与直线28mx y +=-互相垂直的充要条件是m= .6. 若实数对(x ,y )满足约束条件0230x y xx y >⎧⎪≥⎨⎪+-≤⎩,则x y 1+的最小值为 .7. 设a>0,b>0,若3是3a 与3b 的等比中项,则1a +1b的最小值是______8.抛掷甲、乙两枚质地均匀且四面上分别标有1,2,3,4的正四面体,其底面落于桌面,记所得的数字分别为x ,y ,则x y为整数的概率是 .9.若ABC 的三边长分别为a, b, c ,其内切圆半径为r ,则S △ABC=12 (a+b+c )·r ,类比这一结论到空间,写出三棱锥中的一个正确结论为10.若A 是锐角三角形的最小内角,则函数A A y sin 2cos -=的值域为 . 11.设,αβ为互不重合的平面,,m n 为互不重合的直线,给出下列四个命题: ①若,,m n m n αα⊥⊂⊥则;②若,,m n m αα⊂⊂∥,n β∥β,则α∥β; ③若,,,,m n n m n αβαβαβ⊥⋂=⊂⊥⊥则; ④若,,//,//m m n n ααββ⊥⊥则. 其中正确命题的序号为12.已知椭圆的中心在坐标原点,焦点在x 轴上,以其两个焦点和短轴的两个端点为顶点的四边形是一个面积为4的正方形,设P 为该椭圆上的动点,C 、D 的坐标分别是())0,,则⋅的最大值为 .13. 在平面直角坐标系xOy 中,设直线2my =+和圆222x y n +=相切,其中m ,*0||1n m n ∈<-≤N ,,若函数1()x f x m n +=- 的零点0(,1),x k k k ∈+∈Z ,则k= .14.已知函数x x x x f 4341ln )(+-=,2()2 4.g x x bx =-+若对任意1(0,2)x ∈,存在[]21,2x ∈,使12()()f xg x ≥,则实数b 取值范围是二、解答题(共6小题,共90分)15.(本小题满分14分)在△ABC 中,c b a ,,分别为角A 、B 、C 的对边,58222bcb c a -=-,a =3,△ABC 的面积为6⑴求角A 的正弦值; ⑵求边b 、c ; 16.(本小题满分14分)如图,AB 为圆O 的直径,点E 、F 在圆O 上,且//AB EF ,矩形ABCD 所在的平面和圆O 所在的平面互相垂直,且2AB =,1AD EF ==. (1)求证:AF ⊥平面CBF ;(2)设FC 的中点为M ,求证://OM 平面DAF ;(3)设平面CBF 将几何体EFABCD 分成的两个锥体的体积分别为F ABCD V -,F CBE V -, 求:F ABCD F CBE V V --17.(本小题满分14分)如图:设工地有一个吊臂长15DF m =的吊车,吊车底座FG 高1.5m ,现准备把一个底半径为3m 高2m 的圆柱形工件吊起平放到6m 高的桥墩上,问能否将工件吊到桥墩上?(参考数据:30.20.58,0.660.81≈≈)18.(本小题共16分)已知椭圆()222210x y a b a b +=>>和圆O :222x y b +=,过椭圆上一点P 引圆O 的两条切线,切点分别为,A B .(1)①若圆O 过椭圆的两个焦点,求椭圆的离心率e ; ②若椭圆上存在点P ,使得90APB ∠=,求椭圆离心率e 的取值范围;(2)设直线AB 与x 轴、y 轴分别交于点M ,N ,求证:2222a b ONOM+为定值.C D BA EG H19.(本小题共16分)已知M (p, q )为直线x+y-m=0与曲线y=-1x 的交点,且p<q ,若f (x )=2x-m x2+1 ,λ、μ为正实数。
江苏省G4(苏州中学、盐城中学、扬州中学、常熟中学)2021届高三期末调研卷英语解析
苏高中,常熟省中,盐城中学,扬州中学四校联考解析A篇是一篇应用文,首先说明在生意场上喝酒的不可避免性,再从“喝什么”、“勇气、数量、质量”和“一般的礼节”三个方面介绍中国的饮酒文化。
文章理解容易,比较简单。
B篇是一篇议论文,阐述了在现代化喧嚣的城市中独处的必要性和独处的难点,作者呼吁人们多一点独处。
文章需要一定的理解力,难度中等。
C篇阅读讲的是某国接种疫苗的举措,且数据证实了有效性。
主要考察段落理解,较容易定位,难度中等。
D篇文章从随身听的起源和优缺点谈起,引申出关于公共场合缓解孤独的建议,呼吁人们适当的和陌生人进行交流。
总体考察文章大意的理解,难度中等偏上。
龚露老师详细解析:A篇第21题C 推断题。
啤酒是清凉的,清爽的淡啤酒可以冷却喝白酒的灼热感,所以啤酒是辅助性饮料,辅助白酒,A是开胃菜,B是主要酒水,C是辅助酒水,D是饭后酒水,故选C。
第22题D 推断题。
由文章第五段可知,与人喝酒时底线是,最好喝他们给的任何东西,这叫做“勇气”,即是“酒胆”,底线可以推断出重要的,而且在该段最后明确提出了该点是最重要的,故选D。
第23题C 细节题。
由文章最后一段可知,碰杯时,年轻人应该比年长者举的杯更低,而且如果年轻人比那些迟到的人迟到,那就被认为是极其严重的酒后惩罚,junior对应a young adult,故选C。
B篇第24题D 推断题。
文章第一段提出了一个情景,一个人的桌子,这样的一顿饭总是让人“刮目相看”,但是人们通常都是和他的伙伴一起吃饭,独处是一种奢华的选择,一个人的桌子通常会招致不赞同的目光,D正确,A项all the time无法体现。
第25题A 主旨大意题。
文章第二段主要介绍了现代化生活中我们的时间被各种社交充斥,我们失去了独处的时间,与此对比,阐述了独处的好处—用自己的方式来处理,故选A。
第26题B 细节题。
由文章第三段可知,性格内向者通过与个人思想的相处反思补充个人的能量释放个性特质,sit alone with my thoughts对应reflect on their own thoughts。
2021年江苏省扬州中学高三英语上学期期末考试试卷及参考答案
2021年江苏省扬州中学高三英语上学期期末考试试卷及参考答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AThe Origins of Famous BrandsOur lives are full of brand names and trademarked products that we use every day. Although many brand names are simple acronyms(首字母缩略词) or versions of their founders names, some of the companies we trust every day actually have fascinating and surprising back stories.StarbucksIt seems fitting that the most famous coffee brand in the world would take its name from one of the world’s greatest works of literature. The inspiration for the name of the coffeehouse came from Herman Melville’sMoby Dick. The founders’ original idea was to name the company after the Captain Ahab’s ship, but they eventually decided that Pequot wasn’t a great name for coffee, so they chose Ahab’s first mate, Starbucks, as the name instead.GoogleGoogle was originally called Backrub, for it searched for links in every corner of the Web. In 1997, when the founders of the company were searching for a new name showing a huge amount of data for their rapidly improving search technology, a friend suggested the word “googol”. When a friend tried to register the new domain (域) name, he misspelled “googol” as “google”.NikeOriginally founded as a distributor for Japanese running shoes, the company was originally named BRS, or Blue Ribbon Sports. In 1971, BRS introduced its own soccer shoe, a model called Nike, which is alsothe name for the Greek goddess of victory. In 1978, the company officially renamed itself as Nike, Inc.The right name is essential to a company’s success, and a great origin story is just as important as a great product. An attractive origin story is one more thing that keeps customers guessing, wondering, and buying its products.1. What is the name of the Captain Ahab’s ship?A. Moby Dick.B. Starbucks.C. Pequot.D. Herman Melville.2. Why did the founders of the Google want to change its name?A. They mistook their name.B. They wanted new customers.C. The company’s original name was too long.D. The company’s search technology was improving rapidly.3. Where does the importance of the origin story of one company lie in?A. It can change the company’s image.B. It can add myth to the company.C. It explains the development of the company to customers.D. It makes customers imagine and purchase its goods.BIn recent years,people have been focusing on the quality of food that children are fed in schools. Former First Lady Michelle Obama worked hard to make school lunches healthier, resulting in new menus that featured less fat and salt, more fruits and vegetables.But high-quality nutrients count for little when there is no time to eat them. Amy Ettinger reports, "There is no national standard on how much time kids get to eat that meal. " And with schools being occupied with test scores, teachers are using every available minute for lesson time, which often leaves kids without enough eating time.This is a problem because the length of the school lunch period is a key factor (因素) in how much nutrition children actually gel. Research has found that having less than 20 minutes for lunch results in children consuming much less of their lunch than those with more than 20 minutes.This is really terrible. For many low-income kids, that cafeteria lunch can represent half their daily energy intake. There's also another terrible message that it's acceptable to wolf down food as fast as possible before rushing off to your next class. Cafeteria time should be a chance to interact with friends, to learn important social skills, to observe and share varieties of food. It should be a break in day, a chance to relax before heading into the afternoon.As Ettinger explains,some parents are hoping the National Parent Teacher Association will address this issue. This, in turn, would help parents push their kids' schools for better lunch time standards. Meanwhile, if you have a kid in this situation, you can help by packing a healthy lunch to spare them the cafeteria lineup. Make the foods easy to eat, provide non-messy snacks that can be eaten in class, put great effort into serving a hearty breakfast, and sit down as a family for dinner whenever possible.4. What did Michelle Obama make efforts to improve?A. The quality of school lunches.B. The performance of school kids.C. The school lunch time kids have.D. The eating habits of school kids.5. What happens to children in American schools?A. They are occupied with many tests.B. They fail to get along with each other.C. They consume more meat than before.D. They have less lunch time than before.6. How are low-income kids influenced by the problem at school?A. They can't go to classes on time.B. They can't have enough energy.C. They can't share different kinds of food.D. They can't hold a positive attitude toward life.7.What can parents do to solve the problem?A. Prepare a better lunch for their kids.B. Stop their kids going to the cafeteria.C. Force schools to make adjustments to lunch.D. Guide their kids on how to pack their own lunch.CEarthquakes are a natural disaster—except when they're man-made. The oil and gas industry has forcefully used the technique known as hydraulic fracturing (水力压裂法) to destroy sub-surface rock and liberate the oil and gas hiding there. But the process results in large amounts of chemical-filled waste water. Horizontal drilling (水平钻孔) for oil can also produce large amount of natural, unwanted salt water. The industry deals with this waste water by pumping it into deep wells.On Monday, the US Geological Survey published for the first time an earthquake disaster map covering both natural and “induced” quakes. The map and a report show that parts of the central United States now face a ground-shaking disaster equal to the famously unstable terrain (不稳定地形) of California.Some 7 million people live in places easily attacked by these man-made quakes, the USGS said The list of places at highest risk of man-made earthquakes includes Oklahoma, Kansas, Texas, Arkansas, Colorado, New Mexico, Ohio and Alabama. Most of these earthquakes are ly small, in the range of magnitude (震级) 3, but some have been more powerful, including a magnitude 5.6 earthquake in 2011 in Oklahoma that was connected to waste water filling.Scientists said they do not know ifthere is an upper limit on the magnitude of man-made earthquakes; this is an area of active research Oklahoma has had prehistoric earthquakes as powerful as magnitude 7.It's not immediately clear whether this new research will change industry practices, or even whether it will surprise anyone in the areas of newly supposed danger. In Oklahoma, for example, the natural rate of earthquakes is only one or two a year, but there have been hundreds since hydraulic fracturing and horizontal drilling, with the waste water filling, became common in the last ten years.8. What kind of human activities can cause earthquakes?A. The man-made produced waste water in the factories.B. The process of digging deep wells in those poor areas.C. The advanced techniques used to deal with waste water.D. The oil or gas industry's work connected with the earth.9. What does the underlined word “induced” in paragraph 2 mean?A. Man-made.B. Reduced.C. Newly-built.D. Controlled.10. How much magnitude can man-made earthquakes reach?A. It's been said as small as magnitude 3.B. It has been said as high as magnitude 7.C. It's being studied without a final conclusion.D. It has risen by an average of magnitude 5. 6.11. What is the best title for the text?A. Natural Earthquakes in America Are Disappearing NowB. 7 Million Americans at Risk of Man-Made EarthquakesC. Time for Oil and Gas Industry Change Their Working PracticeD. More Often Earthquakes as Powerful as Magnitude 7 in AmericaD“Heavy hearts, like heavy clouds in the sky, are best relieved by the letting of a little water, the French writer Antoine de Rivarol wrote. This love letter to the cleansing beauty of a good cry is a comforting thought at atime when the continuing stress of the COVID-19 has added heaviness to each of our lives.Scientifically, de Rivarol's poetic image doesn't, if you'll forgive the words used in the poem, hold water. There's limited research on crying, partly because of the difficulty of copying the behavior of real crying in a lab.But even within the previous studies, there's little evidence to suggest that crying provides a physiological cleansing of poisons in people's body.Psychologists believe the relief of a good cry connects with a different emotional process. “It seems that crying occurs just after the peak of the emotional experience, and crying is associated with this return to homeostasis: the process of maintaining a stable psychological state,” said Lauren Bylsma. He also said holding back tears can have negative physical consequences, including headaches and muscle tension. Such restriction can also limit our experiences of joy, gratitude and other positive emotions if we avoid acknowledging our feelings.For me crying has been easier said than done during the COVID-19. Psychologists say it's normal to feel stopped up by the stresses of the past year. We should find opportunities to release and process our emotions.Watching a tear-jerking movie, having an emotional conversation with a close friend, and writing in a journal are healthy ways toelicita cry. Physical activity like light-footed walking or even dancing can also signal our bodies to release some emotional tightness. We can then open up to the flow of feelings that leave us feeling lighter and refreshed—like a clear sky after a soaking rain.12. What is the weakness of the studies ever clone on crying?A. They were clone in a laboratory setting.B. They cared little about different forms of crying.C. They were always concentrated on people's daily life.D. They showed little about the positive physical effect of crying.13. What is the function of crying according to Lauren Bylsma?A. Curing people of their diseases.B. Keeping emotionally balanced.C. Producing negative mental results.D. Expanding people's experience of joy.14. What does the underlined word “elicit” in the last paragraph mean?A. Produce.B. Postpone.C. Control.D. Repeat.15. What are people advised to do according to the text?A. Learn to hold back their tears wisely.B. Share their emotion with their colleagues.C. Have a good cry when necessary.D. Try to avoid admitting our feelings.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
江苏省G4(苏州中学、盐城中学、扬州中学、常州中学)2021届高三上学期期末调研化学试卷 含答案
+19 2 8 8 1 江苏省G4(苏州中学、盐城中学、扬州中学、常州中学)2021届高三上学期期末调研化学试题可能用到的相对原子质量:H 1 C 12 O 16 S 32 Fe 56一、单项选择题:共 13 题,每题 3 分,共 39 分。
每小题只有一个选项最符合题意。
1.现代社会的发展与进步离不开材料,下列有关材料的说法不正确...的是 A .“中国天眼”球面射电望远镜的钢铁“眼眶”属于新型无机非金属材料B .“天宫二号”的硅太阳能电池板可将光能直接转换为电能C .北京大兴国际机场航站楼的多面体玻璃属于硅酸盐材料D .国庆阅兵仪式上坦克喷涂的聚氨酯涂料属于有机高分子材料2.某酒精检验器的工作原理为 2K 2Cr 2O 7+3C 2H 5OH +8H 2SO 4=3CH 3COOH +2Cr 2(SO 4)3+2K 2SO 4+11H 2O 。
下列说法正确的是A .Cr 元素基态原子的核外电子排布式为[Ar]3d 44S 2B .固态C 2H 5OH 是分子晶体C .H 2O 的电子式为D .K +的结构示意图为3.下列有关物质性质与用途具有对应关系的是A .二氧化硫具有漂白性,可用作制溴工业中溴的吸收剂B .苯的密度比 H 2O 小,可用于萃取碘水中的碘C .Na 具有强还原性,可用于和 TiCl 4 溶液反应制备 TiD .Mg 2Si 3O 8·nH 2O 能与酸反应,可用于制胃酸中和剂阅读下列材料,完成 4-6 题:2021 年 1 月 20 日中国科学院和中国工程院评选出 2020 年世界十大科技进展,排在第四位的是一种可借助光将二氧化碳转化为甲烷的新型催化转化方法:CO 2+4H 2=CH 4+2H 2O ,这是迄今最接近人造光合作用的方法。
4.下列有关CO 2、CH 4的说法正确的是A .CO 2的空间构型是V 形B .电负性由大到小的顺序是O>C>HC .CH 4是极性分子D .CO 2转化为CH 4利用了CO 2的还原性5. CO 2加氢制CH 4的一种催化机理如图,下列说法正确的是A .反应中 La 2O 3 是中间产物B.反应中La2O2CO3 可以释放出带负电荷的CO2·C.H2 经过Ni 活性中心裂解产生活化态H·的过程中ΔS>0D.使用TiO2 作催化剂可以降低反应的焓变,从而提高化学反应速率6.某光电催化反应器如图所示,A 电极是Pt/CNT,B 电极是TiO2。
2021届江苏省扬州中学高三英语上学期期末考试试卷及参考答案
2021届江苏省扬州中学高三英语上学期期末考试试卷及参考答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项ARome can be pricey for travelers, which is why many choose to stay in a hostel (旅社). The hostels in Rome offer a bed in a dorm room for around $25 anight, and for that, you’ll often get to stay in a central location (位置) with security and comfort.Yellow HostelIf I had to make just one recommendation for where to stay in Rome, it would be Yellow Hostel. It’s one of the best-rated hostels in the city, and for good reason. It’s affordable, and it’s got a fun atmosphere without being too noisy. As an added bonus, it’s close to the main train station.Hostel Alessandro PalaceIf you love social hostels, this is the best hostel for you in Rome. Hostel Alessandro Palace is fun. Staff members hold plenty of bar events for guests like free shots, bar crawls and karaoke. There’s also an area on the rooftop for hanging out with other travelers during the summer.Youth Station HostelIf you’re looking for cleanliness and a modern hostel, look no further than Youth Station. It offers beautiful furnishings and beds. There are plenty of other benefits, too; it doesn’t charge city tax; it has both air conditioning and a heater for the rooms; it also has free Wi-Fi in every room.Hotel and Hostel Des ArtistesHotel and Hostel Des Artistes is located just a 10-minute walk from the central city station and it’s close to all of the city’s main attractions. The staff is friendly and helpful, providing you with a map of the city when you arrive, and offering advice if you require some. However, you need to pay 2 euros a day for Wi-Fi.1.What is probably the major concern of travelers who choose to stay in a hostel?fort.B.Security.C.Price.D.Location.2.Which hotel best suits people who enjoy an active social life?A.Yellow Hostel.B.Hostel Alessandro Palace.C.Youth Station Hostel.D.Hotel and Hostel Des Artistes.3.What is the disadvantage of Hotel and Hostel Des Artistes?A.It gets noisy at night.B.Its staff is too talkative.C.It charges for Wi-Fi.D.It’s inconveniently located.BWhen you say the word donkey, whatthings come to your mind? A few people might say they’re cute, but the majority think they’re stubborn, dumb and all-round less capable than their horse s.However, this wasn’t the case for a recently unearthed ancient Chinese noblewoman who was unexpectedly found buried with her donkeys. Published in the journal Antiquity in March, Chinese archaeologists (考古学家) first discovered the tomb in Xi’an, Shaanxi, in 2012. The team examined the remains and identified the body as Cui Shi, a Tang Dynasty high-born lady who died in 878 AD.Speaking to Science Magazine in 2012, the study’s co-author, Fiona Marshall, said the finding caused confusion as “donkeys … are not associated with high-status people”.However, following years of further research, the team discovered artworks and artifacts that showed a sport known as “Lvju”. This was similar to modern-day polo (马球)and was popular among noble (高贵的) women at the time. They preferred to use donkeys instead of full-sized horses for safety reasons, due to their smaller size and slower speed.Speaking to CNN, Marshall later said, “Historical documents also showed that ladies of the late Tang court loved to play donkey polo.”At that time in Chinese history, animals were often placed in tombs so that they could be used for a specific purpose in the afterlife. The study determined that Cui Shi likely requested that her beloved donkeys be buried with her, so that she could continue her favorite sport after death. In total, three donkeys were found inside her tomb with riding gear (装备), including stirrups (马镫). “This context provides evidence that the donkeys in her tomb were for polo, not transport,” lead author Hu Songmei of the Shaanxi Academy of Archaeology told Science Magazine.Before the study, it was believed that donkeys were only used to carry loads, but now it may be time to see them as a sign of achieving high social status(地位), well, in ancient times.4. What do most people think of donkeys, according to the text?A. They are as adorable(可爱的) as horses.B. They are stubborn and not so capable.C. They were necessary in ancient sports.D. They were a sign of high social status.5. Why did Fiona Marshall feel confused when she discovered the donkeys?A. She didn’t connect donkeys with nobles.B. She hadn’t seen donkeys in ancient tombs before.C. She didn’t expect to find donkeys in a woman’s tomb.D. She didn’t understand why animals were in human tombs.6. What do we know about the sport “Lvju” from the text?A. Horses were preferred in Lvju.B Lvju was similar to modern-day soccer.C. Lvju was popular among common people.D. Donkeys were preferred in the sport for safety.7. The donkeys were found in the tomb of Cui Shi probably because _______.A. she intended to use them for transport after deathB. her family didn’t want her to be lonely after deathC. she wanted to continue to play Lvju after deathD. noble women needed donkeys to maintain their dignityCOlder adults with a better sense of smell may live longer than thosewho have a poor sense of smell, a new study suggests. The study was a project of researchers in theUnited Statesthat was ongoing for over 13 years. They asked nearly 2,300 men and women to identify 12 common smells. All the subjects were from 71 to 82 years of age. The researchers gave the adults scores, from 0 to as high as 12, based on how many smells they identified correctly.During the years of follow-up investigation, over 1,200 of the subjects died. When the study was launched, none of the adults were weak. They could walk a little under half a kilometer, climb 10 steps and independently complete daily activities. In the latest findings, the researchers noted that those with a weak nose were 30 percent more likely to die than people with a good sense of smell. The findings were reported last month in the scientific publication Annals of Internal Medicine.Honglei Chen, a doctor withMichiganStateUniversityinEast Lansing,Michigan, was the lead writer of a report on the study. He said the connection between a poor sense of smell and an increased risk of dying was limited to adults who first reported good-to-excellent health. This suggests that a poor sense of smell is an early and sensitive sign for worsening health before it is recognizable in medical tests. With a poor sense of smell, people are more likely to die of brain and heart diseases, but not of cancer or breathing disorders.The results also suggest that a poor sense of smell may be an early warning for poor health in older age that goesbeyond dementia or other neurodegenerative(神经变性的) diseases. These often signal the beginning of a weakening of the mind or body.8. What do you know about the study mentioned?A. The study involved researchers from the world.B. All the participants were of different ages.C. The study began to be performed about 13 years ago.D. 2 ,300 men and women were young and healthy.9. What was the situation like at the beginning of the study?A. More than 1,200 of the participants passed away.B. Many of the subjects were found with health problems.C. All the subjects were independent of others when walking.D. One third of the participants had a poor smell sense.10. What can be inferred from the last two paragraphs?A. People with a poor sense of smell have heart disease.B. You should be careful with your health if you smell poorly.C. People with a poor sense of smell won't suffer from cancer.D. Most of the elder people may have the dementia disease.11. Which is the best title for the passage?A. Strong Sense of Smell May Be Linked to Longer LifeB. Old People Tend to Have a Poor Sense of SmellC. A Number of Factors Result in Longer LifeD. Being Ill Means Losing the Sense of SmellDOne day about eight years ago in the departure lounge (休息室) of a flight from New York's LaGuardia airport to O'Hare in Chicago, I found a young boy in tears and his mother at his side also appeared upset, I walked to them and invited them to our VIP lounge.As it turned out, the boy, Miles and his mom were returning to their home in Kansas City. Miles has had some health problems. Though he had received more than thirty operations in a Jewish Hospital in New York, he would be back for more.Miles enjoyed spending his time in our VIP lounge looking at the entire wall filled with the pictures of many celebrities (名人) who often came to our office. We soon added Miles' picture to the wall among those celebrities.Among the celebrities, Miles like the country singer Garth Brooks best. Miles would just sit and stare at Garth's picture,Oneday, Mr. Brooks was waiting in the lounge for his flight. As he looked at the collection of photographs, Garth asked about the youngster with the big smile. We told him about Miles. We also told him how much Miles loved and respected (尊重) him. He nodded and left.About six months later, Garth was going to be performing in Kansas City and he asked our workers to help him get in touch with the family. He wanted Miles to be his guest. That evening, not only did Miles sit in the front row, but he and Garth also had a private meeting after the performance.Although Miles would receive many more treatments after that special evening, his smile greeted us with every following visit. The face of a sick boy was changed by the joy of a stranger.12. What does the author probably do?A. A worker at an airport.B. A killed photographer.C. A country music singer.D. A doctor in a Jewish hospital.13. What did Miles enjoy doing in the VIP lounge?A. Interviewing celebrities he saw there.B. Seeing pictures of celebrities on the wall.C. Drawing pictures of the celebrities there.D. Singing together with his favorite singer.14. Which words can best describe Garth Brooks?A. Determined and generous.B. Proud and selfish.C. Kind and helpful.D. Powerful and rich.15. What can be the best title for the text?A. Importance of Good ServiceB. Kindness from StrangersC. A Serious Health ProblemD. A Helpless Mother第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
2021年G4学校高三教学情况期末调研 语文
盐城中学·苏州中学·扬州中学·常州中学2021年G4学校高三教学情况期末调研语文2021.01一、现代文阅读(一)现代文阅读Ⅰ(本题共5小题,19分)阅读下面的文字,完成1-5题。
材料一:高尔基说:“一般说来,神话乃是自然现象,对自然的斗争,以及社会生活在广大的艺术概括中的反映。
”这就说明了神话的产生,是基于现实生活,而并不是出于人类头脑里的空想。
所以当我们研究神话的起源,古代每一时期的神话所包含的特定意义等诸如此类的问题的时候,都不能离开当时人类的现实生活、劳动和斗争而作凭空的推想。
中国神话的“源”,求诸古籍记载,自然最早莫过于属于巫书性质的《山海经》。
它实际上是从战国初年到汉代初年这一段长时间内众多无名氏的作品,初步推断可能是楚地和巴地的人所作,有巫师和文人参与其事。
但是追本溯源,还应当推寻到传说中夏禹、伯益那个历史时代。
好些神话故事经由那个时代的酋长而兼巫师身份的人物,口头直接传承下来乃是大有可能的。
根据我的研究,万物有灵论时期已是神话的初步发展阶段,《山海经》所记载的神话,大都属此阶段。
但在前万物有灵论时期,即已有萌芽状态的神话产生了。
这个时期相当于马克思在《摩尔根﹤古代社会﹥一书摘要》中所说的蒙昧时期的中级阶段,亦即以生产方式为分期的旧石器时期的中期。
这个时期产生的神话,多以动植物为主要描述的对象,尤其着重叙写的是动物,性质和后世的童话、寓言相近。
我称这个时期的神话为活物论神话,以别于万物有灵论时期的神话。
那时候的人们,刚从动物分离出来不久,还存在着物我混同的原始思维的心理状态,视眼前的万物,不论是动物植物,或山川日月星辰风雨云霞等,都认为是和自己一样有生命有意志的活物,由此而在集体无意识中产生的叙写它们之间或它们与人类交往的故事,就是最早时期的神话——活物论神话。
原始的宗教思想萌芽于此,图腾主义也由此而来。
但《山海经》保留这种神话已经不多了,只还有两三个残片遗存其中,较多的是保留在先秦时代的寓言里。
【生物】江苏省G4(苏州中学、盐城中学、扬州中学、常州中学)2021届高三上学期期末调研(解析版)
一、单项选择题:共15题,每题2分,共30分。每题只有一个选项最符合题意。
1.下列关于细胞中化合物的叙述,错误的是()
A.糖原、纤维素酶和脂肪酸的组成元素都主要是C、H、O
B.细胞中合成淀粉、蛋白质及核酸的过程都会产生水
2、利用血球计数板在显微镜下直接计数是一种常用的细胞计数法,这种方法可以直接测定样品中全部的细胞数目,所以一般用于单细胞微生物数量的测定,由于血球计数板上的计数室盖上盖玻片后的容积是一定的,所以可根据在显微镜下观察到的细胞数目来计算单位体积的细胞的总数目。
D、碘是甲状腺激素的合成原料,故通过“食盐补碘”可以有效预防“大脖子病”的发生,D正确。
故选A。
2.下列有关利用传统发酵技术制作果酒、果醋及泡菜的叙述,正确的是()
A.发酵原料和发酵装置都需进行灭菌,以防止杂菌污染
B.发酵用菌种的细胞呼吸类型及生物膜系统的组成都是相同的
C.三者的发酵液都主要是因为产生了大量二氧化碳而呈酸性
【详解】A、果酒、果醋及泡菜的制作过程中的产物(酒精、醋酸形成的酸性条件、乳酸形成的酸性条件)能抑制杂菌的繁殖,而且传统发酵技术制作过程中的菌种一般来源于原料中,因此发酵原料不需要灭菌,否则会杀死菌种,A错误;
B、由分析可知,发酵用菌种的细胞呼吸类型不相同,发酵菌种有酵母菌真菌,也有醋酸菌、乳酸菌细菌,真菌有生物膜系统,细菌只有生物膜(细胞膜),B错误;
B、一个mRNA上结合多个核糖体,有利于细胞快速合成相同的蛋白质,提高了翻译的效率,B错误;
C、一种氨基酸可能对应多种密码子,这样使生物体具有一定的容错性,提高翻译效率,C正确;
D、DNA分子中,GC之间能形成三个氢键,故细胞生物DNA中GC含量较高,DNA更稳定,有利于生物生活在较高温度的环境,D正确。
2021届江苏省扬州中学高三英语上学期期末考试试题及答案解析
2021届江苏省扬州中学高三英语上学期期末考试试题及答案解析第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AWhen the sun shines brightly, it provides a great chance to get outdoor things done. Like making hay! At least, that is what farmers from the past would say. ―Make hay while the sun shines.This idiom is very old, dating back to Medieval times. Rain would often ruin the process of making hay. So, farmers had no choice but to make hay when the sun was shining.Today, we all use this expression, not just farmers. When conditions are perfect to get something done, we can say, ―It’s a good idea to make hay while the sun shines.In other words, you are taking advantage of a good situation or of good conditions. You are making the most of your opportunities. These all mean ―making hay while the sun shines.And sometimes we use this expression to mean we beat someone to the punch, or we got ahead of someone else. And other times you make hay while the sun shines to make good use of the chance to do something while it lasts. You are being opportunistic – taking advantage of a good opportunity. For example, my friend Ozzy was sick for a week and could not go to work. So, his co-worker Sarah -- who doesn’t like him -- took advantage of his illness and stole his project! Talk about making hay while the sun shines.Sometimes when you make hay while the sun shines you are staying ahead of a problem – like in this example:Hey, do you want to go hiking with me and my friends this weekend? The weather is going to be beautiful! I wish I could. But I have to finish my taxes. It’s the last weekend before they’re due.Oh, that’s too bad.Wait. What about your taxes?My taxes are done. I was off from work a couple of weeks ago and made hay while the sun shined. I got all of it done!I wish I would have taken advantage of my time off last week___1___All I did was lay around thehouse.And that’s all the time we have for these Words and Their Stories. But join us again next week. You can listen while you’re making dinner or riding to work. Yeah, make hay while the sun shines.1.Which of the following best matches ―make hay whilethe sun shines in paragraph 2?A.Sow nothing, reap nothing.B.Sharp tools make good work.C.Strike while the iron is hot.D.One swallow doesn’t make a summer.2.According to the underlined sentence, what feeling does the speaker express?A.AdmirableB.RegretfulC.AnnoyedD.Indifferent3.Where is the passage probably taken from?A.A radio programB.A magazineC.A brochureD.A novelBWolves have a certain undeserved reputation: fierce, dangerous, good forhunting down deer and farmers’ livestock. However, wolves have a softer, more social side, one that has been embraced by a heart-warming new initiative.In a bid to save some of Europe’s last wolves, scientists have explored the willingness of these supposedly fierce creatures to help others of their kind. Female wolves, the scientists have discovered, make excellent foster parents to wolf cubs that are not their own. The study, published in Zoo Biology, suggests that captive-bred wolfcubs(幼兽)could be placed with wild wolf families, boosting the wild population.The gray wolf was once the world’s most widely distributed mammal, but it became extinct as a result of widespread habitat destruction and the deliberate killing of wolves suspectedof preying on livestock. Fear and hatred of the wolf have since become culturally rooted, fuelled by myths, fables and stories.In Scandinavia, the gray wolf is endangered, the remaining population found by just five animals. As a result, European wolves are severely inbred and have little geneticvariability(变异性), making them vulnerable to threats, such as outbreaks of disease that they can’t adapt to quickly. So Inger Scharis and Mats Amundin of Linkoping University, in Sweden, started Europe’s first gray wolf-fostering program. They worked with wolves keptat seven zoos across Scandinavia. Eight wolf cubs between four and six days old were removed from their natural parents and placed with other wolf packs in other zoos. The foster mothers accepted the new cubs placed in their midst.The welfare of the foster cubs and the wolves’ natural behavior were monitored using a system of surveillance cameras. The foster cubs had a similar growth rate as their step siblings in the recipient litter, as well as their biological siblings in the source litter. The foster cubs had a better overall survival rate, with 73% surviving until 33 weeks, than their biological siblings left behind, of which 63% survived. That rate of survival is similar tothat seen in wild wolf cubs. Scientists believe that wolves can recognize their young, but this study suggests they can only do so once cubs are somewhere between three to seven weeks of age.If captive-bred cubs can be placed with wild-living families, which already have cubs of a similar age, not only will they have a good chance of survival, but they could help dramatically increase the diversity of the wild population, say the researchers. Just like the wild wolves they would join, these foster cubs would need protection from hunting. Their arrival could help preserve the future of one of nature’s most iconic and polarizing animals.4. What’s the theme of the passage?A. Giving wolf cubs a new lifeB. Foster wolf parents and foster cubsC. The fate of wild wolvesD. Changing diversity of wild wolves5. Which of the following flow chart best demonstrates the relationship between the wolves?A. B.C. D.6. Which of the following statements is true?A. Female wolves are willing to raise wolf cubs of 3 to 7 weeks old.B. Foster cubs are accepted by foster parents and are well bred.C. Man’s hostile attitude towards wolves roots in myths, fables and stories.D. Foster cubs and their biological siblings have similar growth rate and survival rate.7. What’s the purpose of the research?A. To help wolves survive various threatsB. To improve wolves’ habitat and stop deliberate killingC. To save endangered wolves by increasing their populationD. To raise man’s awareness of protecting wolvesCHenry Cavill: Bring Superman to LifeHenry Cavill knew that he wanted to be a star at 16 years of age, after a chance meeting with movie star Russell Crowe who inspired hispassion for acting. But for the British-born actor, the bright lights and attraction ofHollywoodwere a long way away. Supported by his secretary mother and stockbroker father, he decided to study drama during high school. His journey to super star began.Before gaining the international recognition he has now, Cavill tried out for roles in the Harry Potter and Twilight series but failed to get either. He would have to keep waiting for his big chance.Determined as ever, Cavill took any acting jobs he could get his hands on and appeared in several low-budget horror movies and TV shows in hopes of getting noticed. It almost worked. In the early 2000s, at just 22 years old, he narrowly missed out on becoming the new James Bond. Finally, in 2007, his hard work paid off. He won a leading role as the first Duke of Suffolk in the period showThe Tudors. The TV show was very popular and helped to raise Cavill's popularity inAmerica.In 2011, Cavil landed his breakout role, playing Superman in the DC Extended Universe. He hasn't looked back and has since starred in many hit films, such asMission: Impossible- Fallout.More recently, he stepped back on to the small screen. Since 2019, he has starred in the popular seriesThe Witcher, adapted from the book series and video games of the same name. In the TV show, Cavill played a brave monster hunter named Geralt of Rivia, which was the perfect role for Cavill because he was a fan of the video games. Cavill also got a chance to play a classic English character — master detective Sherlock Holmes — in 2020'sEnola Holmes.However, Cavill isn't just a good guy on screen. His charity work also makes him a real-life hero. In 2014, he took part in the Ice Bucket Challenge while wearing his full Superman suit to support the ALS Association. Currently, he is an ambassador for the UK's Royal Marines Charity, which supports war veterans (退伍军人). Why does he do it? He love to make people feel good and bring smiles to people' faces. Indeed, Henry Cavill in living proof that you don't always need to wear a cape (斗篷) to act like a hero.8. Why did Cavil act in low-budget film and TV works early in his career?A. He was too polite to refuse.B. He was hoping to get noticed.C. He was encouraged to do so by his parents.D. He was friends with the directors of the projects.9. The role of the monster hunter was the perfect for Cavill because ________ .A. he had experienced hunting monstersB. he had played the same role in a movieC. he knew the writer of the books personallyD. he enjoyed the video games that the show was rooted in10. Which of the following words can best describe Cavill?A. Modest and friendly.B. Determined and kind.C. Talented and faithful.D. Honest and considerate.11. What made Cavill a real-life hero?A. Being a successful actor.B. Playing Superman on screen.C. Devoting to charities.D. Wearing a cape to take part in activities.DCanadaIs Our NeighbourCanada and the United States are neighbours.They are on the same land.They share the same long boundary(国界).These two nations are similar in many ways.Canada buys many goods from the United States.Cars and clothes are two examples.The United States also buys goods from Canada.Much of the paper used in the United States comes from Canada.Some of the oilweuse comes from Canada,too.Americans travel toCanadaon holiday.And Canadians often visit the United States.It is easy for the people of one country to go to the other country.Canadians read about the United States in newspapers and magazines.Many Americans watch Canadian baseball and hockey (曲棍球)matches on Sundays.However,there are important differences between theUnited Statesand Canada.The United States has more people.Because the population is smaller,there are more open places in Canada.There is much unused land.This is another important difference.12.Canadabuys from theUnited States.A.oil and paperB.nothingC.many thingsD.everything13.In the first paragraph “we” means ________.A.CanadiansB.AmericansC.ChineseD.students14.The people in theUnited Stateslike Canadian ________.A.baseballB.basketballC.newspapersD.oil15.Which of the following statements is WRONG?A.Canada has less people than theUSA.B.Canada has not used all the land.C.Canada is connected withAmerica.D.Canadians don’t like hockey.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
2024届江苏省扬州中学高三上学期1月月考英语及答案
江苏省扬州中学2023-2024学年度第一学期高三阶段检测英语2024.1本试卷分四个部分。
满分150分,考试用时120分钟。
第一部分 听力(共两节,满分30分)第一节(共5小题;每小题1.5分,满分7.5分)听下面5段对话。
每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. What will the woman do next?A. Attend a meeting.B. Pick up the man's client.C. Send the man to his office.2. What does the man think of the campus?A. It’s beautiful.B. It's a Greek campus.C. It’s an ancient campus.3. What is the woman?A. A salesperson.B. A hotel clerk.C. A waitress.4. What type of book is the woman reading?A. Science fiction.B. Horror fiction.C. Romantic fiction.5. When will the man probably meet Dr. Banks?A. At 8:20.B. At 8:50.C. At 9:20.第二节(共15小题;每小题1.5分,满分22.5分)听下面5段对话或独白。
每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题将给出5秒钟的作答时间。
每段对话或独白读两遍。
听第6段材料,回答第6、7题。
2021届江苏省G4(苏州中学、盐城中学、扬州中学、常熟中学)高三教学情况期末调研卷 英语(解析版)
2021年G4学校高三教学情况期末调研英语 2021.01注意事项:1.答题前,考生务必将自己的姓名、考试号填写在答题卡上。
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,将答题卡交回,试卷学生自行保管好。
第一部分听力(共两节,满分30分)做题时,先将答案标在试卷上。
录音内容结束后,你将有两分钟的时间将试卷上的答案转涂到答题卡上。
第一节(共5小题;每小题1.5分,满分7.5分)听下面5段对话。
每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. Where is the conversation probably taking place?A.:At school.B. At a cafe.C. At the man's house.2. How will the woman probably get paid?A. In cash.B. Through WeChat.C.By credit card.3. What are the speakers likely to do?A. Hide from the bears.B. Scare the bears away.C. Feed the bears.4. How is the man probably feeling?A.Relaxed.B.Determined.C. Uncertain.5. What is the conversation mainly about?A. Teammates discussing a game.B.A young child talking to her hero.C. A girl asking for advice from her brother.第二节(共15小题;每小题1.5分,满分22.5分)听下面5段对话或独白。
专题29 空间向量与立体几何(解答题)(新高考地区专用)(解析版)
专题29 空间向量与立体几何(解答题)1.如图,在三棱锥P ABC -中,平面PAC ⊥平面ABC ,PC AC ⊥,BC AC ⊥,2AC PC ==,4CB =,M 是PA 的中点.(1)求证:PA ⊥平面MBC ;(2)设点N 是PB 的中点,求二面角N MC B --的余弦值.【试题来源】陕西省咸阳市2020-2021学年高三上学期高考模拟检测(一)(理)【答案】(1)证明见解析;(2)3. 【解析】(1)平面PAC ⊥平面ABC ,平面PAC平面ABC =AC ,BC ⊂平面ABC ,BC AC ⊥,所以BC ⊥平面PAC ,因为PA ⊂平面PAC ,所以BC PA ⊥,因为AC PC =,M 是PA 的中点,所以CM PA ⊥, 因为CMBC C =,,CM BC ⊂平面MBC ,所以PA ⊥平面MBC .(2)因为平面PAC ⊥平面ABC ,平面PAC平面ABC =AC ,PC ⊂平面PAC ,PC AC ⊥,所以PC ⊥平面ABC ,因为BC ⊂平面ABC ,所以PC BC ⊥,以C 为原点,CA ,CB ,CP 为x ,y ,z 轴正方向,建立如图所示的空间直角坐标系,(2,0,0)A ,(0,4,0)B ,(0,0,0)C ,(0,0,2)P ,(1,0,1)M ,(0,2,1)N ,则(1,0,1)CM =,(0,2,1)CN =,(2,0,2)PA =-,由(1)知(2,0,2)PA =-是平面MBC 的一个法向量,设(,,)n x y z =是平面MNC 的法向量,则有00CM n CN n ⎧⋅=⎨⋅=⎩,即020x z y z +=⎧⎨+=⎩,令1y =,则2z =-,2x =,所以(2,1,2)n =-,设二面角N MC B --所成角为θ,由图可得θ为锐角,则2cos cos ,||||PA n PA n PA n θ⋅⨯=<>===【名师点睛】解题的关键是熟练掌握面面垂直的性质定理,线面垂直的判定和性质定理,并灵活应用,处理二面角或点到平面距离时,常用向量法求解,建立适当的坐标系,求得所需点的坐标及向量坐标,求得法向量坐标,代入夹角或距离公式,即可求得答案. 2.在四棱锥P ABCD -中,PAB △为直角三角形,90APB ∠=︒且12PA AB CD ==,四边形ABCD 为直角梯形,//AB CD 且DAB ∠为直角,E 为AB 的中点,F 为PE 的四等分点且14EF EP =,M 为AC 中点且MF PE ⊥.(1)证明:AD ⊥平面ABP ;(2)设二面角A PC E --的大小为α,求α的取值范围. 【试题来源】山东省德州市2020-2021学年高三上学期期末 【答案】(1)证明见解析;(2),32ππα【解析】(1)取PE 的中点N ,连接AN ,DN ,CE ,如图所示:因为12AE AB =,12AP AB =,所以AP AE =,AN PE ⊥.因为四边形ABCD 为直角梯形,且90DAB ∠=︒,12CD AB =, 所以四边形AECD 为正方形,即M 为DE 的中点. 因为14EF EP =,N 为PE 的中点,所以F 为EN 的中点.所以//MF DN . 因为MF PE ⊥,所以DN PE ⊥.所以PE DN PE ANPE DN AN N ⊥⎧⎪⊥⇒⊥⎨⎪⋂=⎩平面ADN . 因为DA ⊂平面ADN ,所以PE DA ⊥.所以DA AB DA PEDA PE AB E ⊥⎧⎪⊥⇒⊥⎨⎪⋂=⎩平面ABP . (2)以A 为原点,AB ,AD 分别为y ,z 轴,垂直AB 的直线为x 轴,建立空间直角坐标系,如图所示:设AD a =,1PA CD ==,2AB =,则()0,0,0A,1,02P ⎫⎪⎪⎝⎭,()0,1,0E ,()0,1,C a . 31,02AP ⎛⎫= ⎪ ⎪⎝⎭,()0,1,AC a =,1,02PE ⎛⎫=- ⎪ ⎪⎝⎭,()0,0,CE a =-. 设平面PAC 的法向量()111,,n x y z =,则1111310220AP n x yAC n y az ⎧⋅=+=⎪⎨⎪⋅=+=⎩,令1y =,解得11x =,1z =,故1,3,n⎛=- ⎝⎭. 设平面PEC 的法向量()222,,m x y z =,则222310220PE mx y CE m az ⎧⋅=-+=⎪⎨⎪⋅=-=⎩,令2y =21x =,20z =,故()1,3,0m =.由图知,二面角A PC E --的平面角α为锐角,所以11cos 0,2α-⎛⎫==⎪⎝⎭.故,32ππα.3.如图,在四棱锥P ABCD -中,底面ABCD 为直角梯形,AD BC ∥,112BC AD ==且CD =E 为AD 的中点,F 是棱PA 的中点,2PA =,PE ⊥底面ABCD .AD CD ⊥(1)证明://BF平面PCD ; (2)求二面角P BD F --的正弦值;(3)在线段PC (不含端点)上是否存在一点M ,使得直线BM 和平面BDF 所成角的正弦值为13?若存在,求出此时PM 的长;若不存在,说明理由. 【试题来源】天津市滨海七校2020-2021学年高三上学期期末联考 【答案】(1)证明见解析;(2(3)存在,7PM = 【解析】(1)由题意得//BC DE ,=BC DE ,90ADC ∠=︒,所以四边形BCDE 为矩形, 又PE ⊥面ABCD ,如图建立空间直角坐标系E xyz -,则()0,0,0E ,()1,0,0A,()B ,()1,0,0D -,(P ,()C -,1,0,22F ⎛ ⎝⎭,设平面PCD的法向量为(),,m x y z=,()0,DC =,(DP =则00DC m DP m ⎧⋅=⎨⋅=⎩,则0x ==⎪⎩,则0y =,不妨设x =1z =,可得()3,0,1m =-,又1,22BF ⎛⎫= ⎪ ⎪⎝⎭,可得0BF m ⋅=,因为直线BF ⊄平面BCD ,所以//BF 平面BCD .(2)设平面PBD 的法向量为()1111,,x n y z =,()1,DB =,(0,BP =,则1100DB n BP n ⎧⋅=⎪⎨⋅=⎪⎩,即111100x ⎧+=⎪⎨+=⎪⎩,不妨设x =()13,1,1n =--,设平面BDF 的法向量为()2222,,n xy z =,32DF ⎛= ⎝⎭,则2200DB n DF n ⎧⋅=⎪⎨⋅=⎪⎩,即222203022x x z ⎧+=⎪⎨+=⎪⎩,不妨设2x =,可得()2n =-,因此有121212cos ,65n n n n n n ⋅==-⋅,(注:结果正负取决于法向量方向) 于是21212465sin ,1cos ,n n n n =-=,所以二面角P BD F --.(3)设((),PM PC λλλ==-=-,()0,1λ∈(),BM BP PM λ=+=-,由(2)可知平面BDF 的法向量为()23,1,3n =-,2223cos ,BM n BM n BM n⋅===⋅,有23410λλ-+=,解得1λ=(舍)或13λ=, 可得1,333PM ⎛=-- ⎝⎭,所以73PM =. 4.在四棱锥P ABCD -中,PA ⊥平面ABCD ,PA =//DC AB ,90DAB ∠=︒,3AB =,2AD CD ==,M 是棱PD 的中点.(1)求异面直线DP 与BC 所成的角的余弦值; (2)求AM 与平面PBC 所成的角的大小;(3)在棱PB 上是否存在点Q ,使得平面QAD 与平面ABCD 所成的锐二面角的大小为60°?若存在,求出AQ 的长;若不存在,说明理由.【试题来源】天津市南开中学2020-2021学年高三上学期第四次月考 【答案】(1;(2)45︒;(3)125. 【解析】如图,以,,AD AB AP 所在直线分别为,,x y z 轴建立如图所示空间直角坐标系,则(()()()()(,0,0,0,3,0,0,2,2,0,0,2,0,P A B C D M ,(1)(0,DP =-,()1,2,0BC =-,所以cos,DP BC==,即异面直线DP与BC(2)(AM=,(3,0,PB=-,()1,2,0BC=-设平面PBC的法向量(),,m x y z=,则mPBm BC⎧⋅=⎨⋅=⎩,3020xx y⎧-=⎪⎨-+=⎪⎩,所以可取(m=,设AM与平面PBC所成的角为θ,则sin cos,AM mθ===,所以AM与平面PBC所成的角为45︒;(3)平面ABCD的法向量可取()10,0,1n=,设(()3,0,3,0,PQ PBλλλ==-=-,则()3Qλ,所以()3AQλ=,()0,2,0AD =,设平面QAD的法向量为()2222,,n x y z=,则22nAQn AD⎧⋅=⎪⎨⋅=⎪⎩,()2223020x zyλ⎧+=⎪⎨=⎪⎩,可取()223,0,3nλ=-,因为平面QAD与平面ABCD所成的锐二面角的大小为60°.所以121cos,2n n=,12=,解得25λ=或2λ=-(舍)所以6,0,55AQ⎛=⎝⎭,所以61255AQ⎛==5.如图,在正四面体A BCD-中,点E,F分别是,ABBC的中点,点G,H分别在,CD AD 上,且14DH AD=,14DG CD=.(1)求证:直线,EH FG 必相交于一点,且这个交点在直线BD 上; (2)求直线AB 与平面EFGH 所成角的正弦值.【试题来源】陕西省榆林市2020-2021学年高三上学期第一次高考模拟测试(理) 【答案】(1)证明见解析;(2. 【解析】(1)因为//,//EF AC GH AC ,11=,=24EF AC GH AC ,所以//GH EF 且12GH EF =,故E ,F ,G ,H 四点共面,且直线,EH FG 必相交于一点,设=EH FG M ,因为,∈M EH EH平面ABD ,所以M ∈平面ABD ,同理:M ∈平面BCD ,而平面ABD ⋂平面BCD BD =,故M ∈平面BCD ,即直线,EH FG 必相交于一点,且这个交点在直线BD 上; (2)取BD 的中点O ,则,⊥⊥BD OA BD OC ,所以BD ⊥平面AOC ,不妨设OD =,则BD AC ==12AO CO ==, 所以1441441921cos 212123+-∠==⨯⨯AOC ,以O 为坐标原点建立如图所示的空间直角坐标系,则(0,(12,0,0),(6,--A B C F G ,故=BA ,(=-FG ,(8,0,=-AC ,(4,0,=-EF ,设平面EFGH 的法向量为(,,)n x y z =,由00n EF n FG ⎧⋅=⎨⋅=⎩可得50y x ⎧+=⎪⎨-=⎪⎩,令x =,则(52,=n ,则182cos ,3||||92⋅<>===⨯BA n BA n BA n ,故直线AB 与平面EFGH . 6.如图,已知四边形ABCD 为菱形,对角线AC 与BD 相交于O ,60BAD ∠=︒,平面ADEF平面BCEF =直线EF ,FO ⊥平面ABCD ,22BC CE DE EF ====(1)求证://EF DA ;(2)求二面角A EF B --的余弦值.【试题来源】江西省五市九校协作体2021届高三第一次联考 【答案】(1)证明见解析;(2)35. 【解析】(1)因为四边形ABCD 为菱形,所以//AD BC ,AD ⊄平面BCEF ,BC ⊂平面BCEF ,//AD ∴平面BCEF ,因为平面ADEF平面BCEF =直线,EF AD ⊂平面ADEF ,所以//EF AD ;(2)因为四边形ABCD 为菱形,所以AC BD ⊥,因为OF ⊥平面ABCD ,所以以O 为坐标原点、OA ,OB ,OF 为x ,y ,z 轴建立空间直角坐标系,取CD 中点M ,连EM ,OM ,60BAD ︒∠=,21BC OA OC OB OD =∴====,2BC CD CE DE CDE ====∴为正三角形,EM =11//,=,//,=22OM BC OM BC EF BC EF BC,//,=//,=EF OM EF OM OF EM OF EM∴∴,从而1(0,1,0),((0,1,0),(22A B C D E---,设平面ADEF一个法向量为(,,)m x y z=,则m DAm DE⎧⋅=⎨⋅=⎩,即12yx y⎧+=⎪⎨+=⎪⎩,令11,(1,x y z m=∴===-,设平面BCEF一个法向量为(,,)n x y z=,则n BCn EC⎧⋅=⎨⋅=⎩,即122yx y⎧-=⎪⎨-+-=⎪⎩,令11,(1,3,1)x y z n=∴==-=--,3cos,5|||,|m nm nm n⋅∴<>==,因此二面角A EF B--的余弦值为35.7.如图,在四棱锥P ABCD-中,90BAD∠=,//AD BC,PA AD⊥,PA AB⊥,122PA AB BC AD====.(1)求证://BC平面PAD;(2)求平面PAB与平面PCD所成锐二面角的余弦值.【试题来源】北京房山区2021届高三上学期数学期末试题【答案】(1)证明见解析;(2【解析】(1)解法1.因为//BC AD,BC⊄平面PAD,AD⊂平面PAD,所以//BC平面PAD,解法2.因为PA AD⊥,PA AB⊥,AD AB⊥,所以以A为坐标原点,,,AB AD AP所在直线分别为x轴、y轴、z轴,建立如图所示空间直角坐标系A xyz-,则(0,0,0),(2,0,0),(0,4,0),(0,0,2),(2,2,0)A B D P C ,平面PAD 的法向量为(1,0,0)t , (0,2,0)BC = ,因为 0120000t BC ⋅=⨯+⨯+⨯= ,BC ⊄平面PAD ,所以//BC 平面PAD ; (2)因为PA AD ⊥,PA AB ⊥AD AB ⊥,所以以A 为坐标原点,,,AB AD AP 所在直线分别为x 轴、y 轴、z 轴,建立如图所示空间直角坐标系A xyz -,则(0,0,0),(2,0,0),(0,4,0),(0,0,2),(2,2,0)A B D P C所以平面PAB 的法向量为(0,1,0)n = , 设平面PCD 的法向量为(,,)m x y z =, (2,2,2)PC =-,(0,4,2)PD =- ,所以2220042020x y z x y m PC m PC y z z y m PD m PD ⎧⎧+-==⎧⎧⊥⋅=⇒⇒⇒⎨⎨⎨⎨-==⊥⋅=⎩⎩⎩⎩,令1(1,1,2)y m ==得 ,cos ,1n mn m n m ⋅<>===⨯,设平面PAB 与平面PCD 所成角为θθ,为锐角, 所以cos θ=. 8.如图,在四棱锥P ABCD -中,底面ABCD 为菱形,平面PAD ⊥平面ABCD ,PA PD ⊥,PA PD =,3BAD π∠=,E 是线段AD 的中点,连结BE .(1)求证:BE PA ⊥;(2)求二面角A PD C --的余弦值;(3)在线段PB 上是否存在点F ,使得//EF 平面PCD ?若存在,求出PF PB 的值;若不存在,说明理由.【试题来源】北京市朝阳区2021届高三上学期期末数学质量检测试题【答案】(1)证明见解析;(2)7-;(3)存在;12PF PB =. 【解析】(1)因为四边形ABCD 为菱形,所以AB AD =.因为3BAD π∠=,E 为AD 的中点,所以BE AD ⊥. 因为平面PAD ⊥平面ABCD ,平面PAD平面ABCD AD =,所以BE ⊥平面PAD . 因为PA ⊂平面PAD ,所以BE PA ⊥.(2)连结PE .因为PA PD =,E 为AD 的中点,所以PE AD ⊥.由(1)可知BE ⊥平面PAD ,所以BE AD ⊥,PE BE ⊥.设2AD a =,则PE a =.如图,建立空间直角坐标系E xyz -.所以(,0,0),,0),(2,0),(,0,0),(0,0,)A a B C a D a P a --.所以),0(D C a =-,(,0,)D a P a =.因为BE ⊥平面PAD ,所以(0,,0)EB =是平面PAD 的一个法向量.设平面PCD 的法向量为(,,)x y z =n ,则00n DC n DP ⎧⋅=⎨⋅=⎩,即00ax ax az ⎧-+=⎪⎨+=⎪⎩,所以,.x x z ⎧=⎪⎨=-⎪⎩令3x =,则1y =,z =(3,1,n =.所以cos ,||||7n EB n EB n EB ⋅===.由题知,二面角A PD C --为钝角,所以其余弦值为- (3)当点F 是线段PB 的中点时,//EF 平面PCD .理由如下: 因为点E ∈/平面PCD ,所以在线段PB 上存在点F 使得//EF 平面PCD 等价于0EF ⋅=n .假设线段PB 上存在点F 使得//EF 平面PCD .设([0,1])PF PBλλ=∈,则PF PB λ=.所以(0,0,),),)EF EP PF EP PB a a a a a λλλ=+=+=+-=-.由)0EF a a a λ⋅=-=n ,得12λ=. 所以当点F 是线段PB 的中点时,//EF 平面PCD ,且12PF PB =. 9.如图,在四棱锥P ABCD -中,PD ⊥平面ABCD ,4PD =,底面ABCD 是边长为2的正方形,E ,F 分别为PB ,PC 的中点.(1)求证:平面ADE ⊥平面PCD ;(2)求直线BF 与平面ADE 所成角的正弦值.【试题来源】北京市东城区2021届高三上学期期末考试【答案】(1)证明见解析;(2)15. 【解析】(1)因为PD ⊥平面ABCD ,所以PD AD ⊥.因为底面ABCD 是正方形,所以AD CD ⊥.因为PD CD D ⋂=,所以AD ⊥平面PCD .因为AD ⊂平面ADE ,所以平面ADE ⊥平面PCD .(2)因为PD ⊥底面ABCD ,所以PD AD ⊥,PD CD ⊥.因为底面ABCD 是正方形,所以AD CD ⊥.如图建立空间直角坐标系D xyz -.因为4PD =,底面ABCD 为边长为2的正方形,所以()0,0,4P ,()2,0,0A ,()2,2,0B ,()0,2,0C ,()0,0,0D ,()1,1,2E ,()0,1,2F . 则()2,0,0DA =,()1,1,2DE =,()2,1,2BF =--.设平面ADE 的法向量(),,m x y z =,由00m DA m DE ⎧⋅=⎨⋅=⎩,可得2020x x y z =⎧⎨++=⎩. 令1z =-,则0x =,2y =.所以()0,2,1m =-.设直线BF 与平面ADE 所成角为θ,则,sincos ,9BF mBF m BF m θ====.所以直线BF 与平面ADE . 【名师点睛】本题考查了面面垂直的判定,核心是要求面面垂直,先考虑线面垂直;同时也考查了线面角的计算方法,核心是要求正弦值,先求余弦值.10.如图,已知11ABB A 是圆柱1OO 的轴截面,O 、1O 分别是两底面的圆心,C 是弧AB 上的一点,30ABC ∠=,圆柱的体积和侧面积均为4π.(1)求证:平面1ACA ⊥平面1BCB ;(2)求二面角11B A B C --的大小.【试题来源】江西省吉安市2021届高三大联考数学(理)(3-2)试题【答案】(1)证明见解析 ;(2)60 .【解析】(1)因为1AA 是圆柱的母线,所以1AA ⊥平面ABC ,因为BC ⊂平面ABC , 所以1AA BC ⊥,又C 是弧AB 上的一点,且AB 是圆O 的直径,所以AC BC ⊥,因为1AA AC A =,所以BC ⊥平面1ACA ,又BC ⊂平面1BCB ,所以平面1ACA ⊥平面1BCB ;(2)设圆柱的底面半径为r ,母线长为l ,因为圆柱的体积和侧面积均为4π,所以2244rl r l ππππ=⎧⎨=⎩,解得,2r ,1l =,即4AB =,11AA =,因为30ABC ∠=,所以2AC =,BC =设圆柱过C 点的母线为CD ,以C 为原点,CA ,CB ,CD 所在直线分别为x 轴、y 轴、z 轴建立空间直角坐标系C xyz -,如图所示;则()0,0,0C ,()B ,()12,0,1A ,()1B ;所以()12,0,1CA =,()10,CB =,()12,BA =-,()10,0,1BB = 设平面11CA B 的法向量为(),,n x y z =,由1120000x z n CA n CB z ⎧+=⎧⋅=⎪⎪⇒⎨⎨⋅=+=⎪⎪⎩⎩,取z =x =1y =-,所以平面11CA B的一个法向量为(3,n =--, 设平面11BA B 的法向量为(),,m a b c=,由1102000m BA a c m BB c ⎧⎧⋅=-+=⎪⎪⇒⎨⎨⋅==⎪⎪⎩⎩, 取1b =,则a =0c ,所以平面11BA B 的一个法向量为()3,1,0m =, 所以1cos ,23n mm n n m ⋅===-+⋅, 由图中可看出二面角11B A B C --是锐角,故二面角11B A B C --的值为60.【名师点睛】证明面面垂直的方法:(1)利用面面垂直的判定定理,先找到其中一个平面的一条垂线,再证明这条垂线在另外一个平面内或与另外一个平面内的一条直线平行即可; (2)利用性质://,αββγαγ⊥⇒⊥(客观题常用);(3)面面垂直的定义(不常用); (4)向量方法:证明两个平面的法向量垂直,即法向量数量积等于0.11.如图1,正方形ABCD ,边长为a,,E F 分别为,AD CD 中点,现将正方形沿对角线AC 折起,折起过程中D 点位置记为T ,如图2.(1)求证:EF TB ⊥;(2)当60TAB ︒∠=时,求平面ABC 与平面BEF 所成二面角的余弦值.【试题来源】安徽省黄山市2020-2021学年高三上学期第一次质量检测(理)【答案】(1)证明见解析;(2. 【解析】(1)取AC 中点O ,连,,OT OB BT ,因为ABCD 为正方形,所以,AC OT AC OB ⊥⊥,又OT OB O ⋂=,所以AC ⊥平面OBT ,而TB ⊂平面OBT ,所以AC TB ⊥. 又,E F 分别为,AD CD 中点,所以//EF AC ,所以EF TB ⊥;(2)因为60TAB ︒∠=,所以TAB △为等边三角形,TB a =,又2OT OB a ==,所以222TB OB OT =+,即OT OB ⊥. 如图建立空间直角坐标系O xyz -,则,0,0,0,,B E F ⎫⎛⎛⎪ ⎝⎭⎝⎭⎝⎭,220,,0,,,2244EF a EB a ⎛⎫⎛⎫==- ⎪ ⎪⎝⎭⎝⎭,平面ABC 法向量(0,0,1)m =设平面BEF 法向量(,,1)x n y =,由00n EF n EB ⎧⋅=⎨⋅=⎩,00244y ay =⎧+-=⎩,012y x =⎧⎪⎨=⎪⎩,1,0,1,cos ,2||||11mn n m n m n ⋅⎛⎫=<>=== ⎪⋅⎝⎭⋅, 记平面ABC 与平面BEF 所成二面角为θ,则θ为锐角,所以cos 5θ=即平面ABC 与平面BEF . 12.如图所示,四棱柱1111ABCD A B C D -的底面是菱形,侧棱垂直于底面,点E ,F 分别在棱1AA ,1CC 上,且满足113AE AA =,113CF CC =,平面BEF 与平面ABC 的交线为l .(1)证明:直线l ⊥平面1BDD ;(2)已知2EF =,14BD =,设BF 与平面1BDD 所成的角为θ,求sin θ的取值范围.【试题来源】海南省2021届高三年级第二次模拟考试【答案】(1)证明见解析;(2)35⎫⎪⎪⎝⎭.【解析】(1)如图,连接AC ,与BD 交于点O .由条件可知//AE CF ,且AE CF =,所以//AC EF ,因为EF ⊂平面BEF ,所以//AC 平面BEF .因为平面BEF 平面ABC l =,所以//AC l . 因为四棱柱1111ABCD A B C D -的底面是菱形,且侧棱垂直于底面,所以AC BD ⊥,1AC BB ⊥,又1BD BB B ⋂=,所以AC ⊥平面1BDD ,所以l ⊥平面1BDD .(2)如图所示,以O 为坐标原点,分别以OB ,OC 的方向为x ,y 轴的正方向建立空间直角坐标系.设2BD a =,因为1BD BD <,所以02a <<.则OB a =,1DD ==所以(,0,0)B a ,(0,1,0)C,F ⎛ ⎝. 由(1)可知(0,1,0)OC =是平面1BDD的一个法向量,而BF a ⎛=- ⎝, 所以sin cos ,OC BF OC BF OC BF θ⋅=<>===当02a <<35<<,即3sin 5θ⎫∈⎪⎪⎝⎭.【名师点睛】求空间角的常用方法:(1)定义法,由异面直线所成角、线面角、二面角的定义,结合图形,作出所求空间角,再结合题中条件,解对应三角形,即可求出结果;(2)向量法:建立适当的空间直角坐标系,通过计算向量夹角(直线方向向量与直线方向向量、直线方向向量与平面法向量,平面法向量与平面法向量)余弦值,即可求出结果.13.在三棱柱111ABC A B C -中,1AB AC ==,1AA =AB AC ⊥,1B C ⊥平面ABC ,E 是1B C 的中点.(1)求证:平面1AB C ⊥平面11ABB A ;(2)求直线AE 与平面11AAC C 所成角的正弦值.【试题来源】浙江省宁波市2020-2021学年高三上学期期末【答案】(1)证明见解析;(2【解析】(1)由1B C ⊥平面ABC ,AB平面ABC ,得1AB B C ⊥, 又AB AC ⊥,1CB AC C =,故AB ⊥平面1AB C , AB 平面11ABB A ,故平面11ABB A ⊥平面1AB C .(2)以C 为原点,CA 为x 轴,1CB 为z 轴,建立如图所示空间直角坐标系, 则()0,0,0C ,()1,0,0A ,()1,1,0B,又BC =11BB AA == 故11CB =,()10,0,1B ,10,0,2E ⎛⎫ ⎪⎝⎭,()1,0,0CA =, ()111,1,1AA BB ==--,11,0,2AE ⎛⎫=- ⎪⎝⎭,设平面11AAC C 的一个法向量为(),,n x y z =,则100n CA n AA ⎧⋅=⎪⎨⋅=⎪⎩,即00x x y z =⎧⎨--+=⎩,令1y =,则1z =, ()0,1,1n =, 设直线AE 与平面11AAC C 所成的角为θ,故1sin 102nAEn AE θ⋅===,即直线AE 与平面11AAC C14.如图,在平面四边形PABC 中,PA AC ⊥,AB BC ⊥,PA AB ==,2AC =,现把PAC △沿AC 折起,使P 在平面ABC 上的射影为O ,连接OA 、OB ,且OB//AC .(1)证明:OB ⊥平面PAO ;(2)求二面角O PB C --的余弦值.【试题来源】安徽省六安市示范高中2020-2021学年高三上学期教学质量检测(理)【答案】(1)证明见解析;(2) 【解析】(1)PO ⊥平面ABC ,AC ⊂平面ABC ,PO AC ∴⊥,又PA AC ⊥,PAPO P =,所以AC ⊥平面PAO , //OB AC ,所以OB ⊥平面PAO ;(2)在Rt ABC 中,AB =2AC =,则1BC ==,30BAC ∴∠=,在Rt OAB 中,903060OAB ∠=-=,所以12OA AB ==,32OB =,Rt PAO 中,PA =AO =32OP ∴==, 以点O 为坐标原点,OB 、OA 、OP 所在直线分别为x 、y 、z 轴建立空间直角坐标系O xyz -,则0,,02A ⎛⎫ ⎪ ⎪⎝⎭、,02C ⎛⎫ ⎪ ⎪⎝⎭、3,0,02B ⎛⎫ ⎪⎝⎭、30,0,2P ⎛⎫ ⎪⎝⎭,所以33,0,22PB ⎛⎫=- ⎪⎝⎭,32PC ⎛⎫=- ⎪ ⎪⎝⎭,由(1)可知()0,1,0m =为平面POB 的一个法向量,设平面平PBC 的法向量为(),,n x y z =,则有330223202x z x y z ⎧-=⎪⎪⎨⎪-=⎪⎩y x z x ⎧=⎪⇒⎨⎪=⎩,取x =(3,n =-,cos ,717m n m n m n ⋅===-⋅⨯, 由图可知,二面角O PB C --为钝角,所以,二面角O PB C --的余弦值为7-. 15.在四棱锥P ABCD -中,平面PAD ⊥平面ABCD ,底面ABCD 为直角梯形,//,90BC AD ADC ∠=︒,11,2BC CD AD E ===为线段AD 的中点,过BE 的平面与线段,PD PC 分别交于点,G F .(1)求证:GF ⊥平面PAD ;(2)若PA PD ==G为PD 的中点,求平面PAB 与平面BEGF所成锐二面角的余弦值.【试题来源】安徽省名校2020-2021学年高三上学期期末联考(理)【答案】(1)证明见解析;(2.【解析】证明:(1)因为12BC AD =,且E 为线段AD 的中点,所以BC DE =, 因为//BC AD ,所以四边形BCDE 为平行四边形,所以//BE CD ,因为CD ⊂平面,PCD BE ⊂/平面PCD ,所以//BE 平面PCD ,又平面BEGF ⋂平面PCD GF =,所以//BE GF ,又BE AD ⊥,且平面PAD ⊥平面ABCD ,平面PAD平面ABCD AD =, 所以BE ⊥平面PAD ,所以GF ⊥平面PAD ;(2)因为,PA PD E =为线段AD 的中点,所以PE AD ⊥,‘’因为平面PAD ⊥平面ABCD ,所以PE ⊥平面ABCD ,以E 为坐标原点,EA 的方向为x 轴正方向建立如图所示的空间直角坐标系E xyz -;则11(0,0,1),(1,0,0),(0,1,0),(0,0,0),(1,0,0),,0,22P A B E D G ⎛⎫--⎪⎝⎭, 则11(1,0,1),(0,1,1),(0,1,0),(1,0,1),,0,22PA PB BE DP EG ⎛⎫=-=-=-==- ⎪⎝⎭, 设平面PAB 的法向量为()111,,m x y z =,则0{0PA m PB m ⋅=⋅=,,,即11110,0x z y z -=⎧⎨-=⎩, 不妨令11x =,可得(1,1,1)n =为平面BEGF 的一个法向量,设平面BEGF 的法向量为()222,,n x y z =,则0{0BE n EG n ⋅=⋅=,,,即222011022y x z =⎧⎪⎨-+=⎪⎩,,不妨令21x =,可得(1,0,1)n =为平面BEGF 的一个法向量,设平面PAB 与平面BEGF 所成的锐二面角为α,于是有2cos |cos ,|32m n α=〈〉==; 所以平面PAB 与平面BEGF .16.如图所示,在四棱锥S ABCD -中,底面ABCD 是正方形,对角线AC 与BD 交于点F ,侧面SBC 是边长为2的等边三角形,点E 在棱BS 上.(1)若//SD 平面AEC ,求SE EB的值; (2)若平面SBC ⊥平面ABCD ,求二面角B AS C --的余弦值.【试题来源】江苏省G4(苏州中学、常州中学、盐城中学、扬州中学)2020-2021学年高三上学期期末联考【答案】(1)1;(2. 【解析】(1)连结EF ,因为//SD 平面AEC ,SD ⊂平面BSD ,平面BSD ⋂平面AEC EF =,所以//SD EF .因为底面ABCD 是正方形,F 为AC 中点,所以EF 是SD 的中位线,则1SE EB=. (2)取BC 的中点为O ,AD 的中点为M ,连结MO ,则MO BC ⊥, 因为平面SBC ⊥平面ABCD ,平面SBC平面ABCD BC =,OM ⊂平面ABCD , 所以OM ⊥平面SBC .又OS BC ⊥,所以O 为坐标原点.以{},,OS OC OM 为正交基底建立空间直角坐标系O xyz -.则()0,1,2A -,()010B -,,,()0,1,0C,)S,1,022E ⎛⎫- ⎪ ⎪⎝⎭,从而()SC =-,()0,2,2AC =-,()0,0,2AB =-,()3,1,2AS =-. 设平面ASC 的法向量为(),,m x y z =, 则0,0.m SC m AC ⎧⋅=⎪⎨⋅=⎪⎩,即0,0.y y z ⎧+=⎪⎨-=⎪⎩取1x =,则y =z = 所以平面ASC的一个法向量为(1,3,m =.设平面ASB 的法向量为(),,n x y z =, 则0,0.n AB n AS ⎧⋅=⎪⎨⋅=⎪⎩,即20,20.z y z -=⎧⎪+-=取y =1x =-,0z =. 所以平面ASB 的一个法向量为()1,3,0n =-.所以7cos ,7m n m n m n ⋅〈〉==. 因为二面角B AS C --的平面角为锐角,所以二面角B AS C --的余弦值为7. 【名师点睛】本题的核心在考查空间向量的应用,需要注意以下问题:(1)求解本题要注意两点:一是两平面的法向量的夹角不一定是所求的二面角,二是利用方程思想进行向量运算,要认真细心,准确计算.(2)设,m n 分别为平面α,β的法向量,则二面角θ与,m n <>互补或相等.求解时一定要注意结合实际图形判断所求角是锐角还是钝角.17.在三棱锥P ABC -中,底面ABC 为正三角形,平面PBC ⊥平面,1,ABC PB PC D ==为AP 上一点,2,AD DP O =为三角形ABC 的中心.(1)求证:AC ⊥平面OBD ;(2)若直线PA 与平面ABC 所成的角为45︒,求二面角A BD O --的余弦值.【试题来源】山东省威海市2020-2021学年高三上学期期末【答案】(1)证明见解析;(2)5. 【解析】(1)证明:连接AO 并延长BC 交于点E ,则E 为BC 中点,连接PE .如图所示:因为О为正三角形ABC 的中心,所以2,AO OE =又2AD DP =,所以//,DO PE 因为PB PC =,E 为BC 中点,所以,PE BC ⊥ 又平面PBC ⊥平面ABC ,平面PBC 平面ABC BC =,所以PE ⊥平面,ABC 所以DO ⊥平面,ABC AC ⊂平面PBC ,所以,DO AC ⊥又,AC BO DO BO O ⊥⋂=,所以AC ⊥平面OBD .(2)由PE ⊥平面ABC 知,所以45PAE ∠=︒ ,所以,PE AE =所以,ABE PBE ≌ 所以1AB PB BC AC ====,由(1)知,,,EA EB EP 两两互相垂直,所以分别以,,EA EB EP 的方向为,,x y z 轴正方向,建立如图所示空间直角坐标系,则1,0,,0,0,0,,22263A B P D ⎛⎫⎛⎫⎛⎛⎫ ⎪ ⎪ ⎪ ⎪ ⎪ ⎝⎭⎝⎭⎝⎭⎝⎭,10,,02C ⎛⎫- ⎪⎝⎭所以31,,0,2231,,623AB BD ⎛⎫-⎛= ⎪ ⎪⎝⎭=-⎝⎭, 设平面ABD 的法向量为(),,n x y z =, 则302302x y nBD z y n AB x ⎧⋅=-=⎪⎪⎨⎪⋅=-+=⎪⎩,令1,x =可得1y z ==,则()1,3,1n =. 由(1)知AC ⊥平面,DBO 故1,02AC ⎛⎫=-- ⎪ ⎪⎝⎭为平面DBO 的法向量, 所以2cos ,5nAC n AC n AC -⋅===-,由图可知二面角A BD O --的为锐二面角,所以二面角A BDO --的余弦值为5. 18.如图,在几何体ABCDEF 中,四边形ABCD 为等腰梯形,且22AB CD ==,60ABC ∠=︒,四边形ACFE 为矩形,且FB =,M ,N 分别为EF ,AB 的中点.(1)求证://MN 平面FCB;(2)若直线AF 与平面FCB 所成的角为60°,求平面MAB 与平面MAC 所成锐二面角的余弦值.【试题来源】山西省运城市2021届高三上学期期末(理)【答案】(1)证明见解析;(2.【解析】(1)取BC 的中点Q ,连接NQ ,FQ ,则1//2NQ AC ,且12NQ AC =, 又1//2MF AC ,且12MF AC = ,所以//MF NQ 且MF NQ =, 所以四边形MNQF 为平行四边形,所以//MN FQ ,因为FQ ⊂平面FCB ,MN ⊄平面FCB ,所以//MN 平面FCB ;(2)由四边形ABCD 为等腰梯形,且22AB CD ==,60ABC ∠=︒,可得1BC =,AC =90ACB ∠=︒,所以AC BC ⊥.因为四边形ACFE 为矩形,所以AC CF ⊥,所以AC ⊥平面FCB ,所以AFC ∠为直线AF 与平面FCB 所成的角,即60AFC ∠=︒,所以1FC =.因为FB =,所以222FB FC CB =+,所以FC BC ⊥.则可建立如图所示的空间直角坐标系C xyz -,3(3,0,0),(0,1,0),,0,12A B M ⎛⎫ ⎪⎝⎭,所以3,0,1,(3,1,0)2MA AB ⎛⎫=-=- ⎪⎝⎭,设(,,)m x y z =为平面MAB 的法向量,则00MA m AB m ⎧⋅=⎨⋅=⎩,即30230x z x y ⎧-=⎪⎨⎪-+=⎩,取23x =,则(23,6,3)m =为平面MAB 的一个法向量,又(0,1,0)n =为平面MAC的一个法向量, 所以657257cos 571||m n mn m n ⋅〈〉====⨯∣∣, 故平面MAB 与平面MAC 所成锐二面角的余弦值为5719. 19.如图,该多面体由底面为正方形ABCD 的直四棱柱被截面AEFG 所截而成,其中正方形ABCD 的边长为4,H 是线段EF 上(不含端点)的动点,36==FC EB .(1)若H 为EF 的中点,证明://GH 平面ABCD ;(2)若14=EH EF ,求直线CH 与平面ACG 所成角的正弦值. 【试题来源】河南省驻马店市2020-2021学年高三上学期期末考试(理) 【答案】(1)证明见解析;(26. 【解析】(1)证明:取BC 的中点M ,连接HM ,DM .因为该多面体由底面为正方形ABCD 的直四棱柱被截面AEFG 所截而成,所以截面AEFG 是平行四边形,则4=-=DG CF EB .因为36==FC EB ,所以1(26)42=⨯+=HM ,且DG//HM ,所以四边形DGHM 是平行四边形,所以GH //DM .因为DM ⊂平面ABCD ,GH ⊄平面ABCD ,所以//GH 平面ABCD .(2)解:如图,以D 为原点,分别以DA ,DC ,DG 的方向为x 轴、y 轴、z 轴的正方向,建立空间直角坐标系D xyz -,则(4,0,0)A ,(0,4,0)C ,(0,0,4)G ,(3,4,3)H ,(4,4,0)=-AC ,(4,0,4)=-AG ,(3,0,3)=CH .设平面ACG 的法向量为(,,)n x y z =,则440440AC n x y AG n x z ⎧⋅=-+=⎨⋅=-+=⎩,令1x =,得(1,1,1)n =.因为cos ,3||||32⋅〈〉===⨯CH n C n n CH H ,所以直线CH 与平面ACG 所成角的正弦值为3.【名师点睛】本题考查了立体几何中的线面平行的判定和线面角的求解问题,意在考查学生的空间想象能力和逻辑推理能力;解答本题关键在于能利用直线与直线、直线与平面关系的相互转化,通过严密推理证明线线平行从而得线面平行,同时对于立体几何中角的计算问题,往往可以利用空间向量法,通过求解平面的法向量,利用向量的夹角公式求解.20.如图,已知四边形ABCD 和BCEG 均为直角梯形,//AD BC ,//CE BG ,且2BCD BCE π∠=∠=,120ECD ∠=︒.22BC CD CE AD BG ====.(1)求证://AG 平面BDE ;(2)求二面角E BD C --的余弦值.【试题来源】安徽省蚌埠市2020-2021学年高三上学期第二次教学质量检查(理)【答案】(1)证明见解析;(2 【解析】(1)证明:在平面BCEG 中,过G 作GN CE ⊥于N ,交BE 于M ,连DM , 由题意知,MG MN =,////MN BC DA 且12MN AD BC ==, 因为//MG AD ,MG AD =,故四边形ADMG 为平行四边形,所以//AG DM , 又DM ⊂平面BDE ,AG ⊂/平面BDE ,故//AG 平面BDE .(2)由题意知BC ⊥平面ECD ,在平面ECD 内过C 点作CF CD ⊥交DE 于F , 以C 为原点,CD ,CB ,CF 的方向为x ,y ,z 轴的正方向建立空间直角坐标系,不妨设1AD =,则22BC CD CE BG ====.且()0,0,0C ,()2,0,0D ,()0,2,0B ,(E -,设平面EBD 的法向量(),,n x y z =,则由0,0,DE n BD n ⎧⋅=⎨⋅=⎩得30,220,x x y ⎧-=⎪⎨-=⎪⎩ 取1y =,得(1,1,3n =,易知平面BCD 的一个法向量为()0,0,1m =,3cos ,51m nm n m n ⋅==⋅=⋅E BD C --. 21.如图,在四棱锥P ABCD -中,底面ABCD 是边长为2的正方形,M 为PC 的中点.(1)求证://AP 平面BDM ;(2)若PB PC ==CD PC ⊥,求二面角C DM B --的余弦值.【试题来源】河南省湘豫名校2020-2021学年高三上学期1月月考(理)【答案】(1)证明见解析;(2. 【解析】(1)连接AC 交BD 于E ,连接EM ,则E 为AC 中点,所以EM 为APC △的中位线,所以//EM AP ,因为EM ⊂平面BDM ,AP ⊄平面BDM ,所以//AP 平面BDM .(2)在PBC 中,因为2224PB PC BC +==,所以PB PC ⊥,取BC 中点O ,AD 中点F ,连接PO ,OF ,则PO BC ⊥,1PO =,因为BC CD ⊥,CD PC ⊥,BC 、PC ⊂平面PBC ,BC PC C ⋂=,所以CD ⊥平面PBC ,因为PO ⊂平面PBC ,所以CD PO ⊥,因为PO BC ⊥,BC CD C ⋂=,BC 、CD ⊂平面ABCD ,所以PO ⊥平面ABCD ,因为OF ⊂平面ABCD ,所以PO OF ⊥,所以PO ,OF ,OB 两两垂直,如图所示,以O 为原点,OF ,OB ,OP 分别为x 轴,y 轴,z 轴建立空间直角坐标系,则(2,1,0)D -,(0,0,1)P ,(0,1,0)B ,(0,1,0)C -,所以110,,22M ⎛⎫- ⎪⎝⎭,可得112,,22DM ⎛⎫=- ⎪⎝⎭,(2,2,0)BD =-,(2,0,0)CD =.设平面BDM 的法向量为()111,,m x y z =, 则0 0m BD m DM ⎧⋅=⎨⋅=⎩,即11111220112022x y x y z -=⎧⎪⎨-++=⎪⎩,取(1,1,3)m =, 设平面CDM 的法向量为()222,,n x y z =,则00n CD n DM ⎧⋅=⎨⋅=⎩,即222220112022x x y z =⎧⎪⎨-++=⎪⎩,取(0,1,1)n =-,所以222cos ,11||||112m n m nm n ⋅〈〉===⋅⨯, 所以二面角C DM B --的余弦值为11.22.如图所示,矩形ABCD 和梯形BEFC 所在平面互相垂直, //BE CF ,BCF CEF ∠=∠=90°,AD =EF =(1)求证:EF ⊥平面DCE(2)当AB 的长为何值时,二面角A EF C --的大小为60°. 【试题来源】山东省菏泽市2020-2021学年高三上学期期末【答案】(1)证明见解析;(2)60°.【解析】(1)因为平面ABCD ⊥平面BEFC ,平面ABCD 平面BEFC BC =,CD BC ⊥,CD ⊂平面ABCD ,所以CD ⊥平面BEFC ,EF ⊂平面BEFC ,从而CD EF ⊥. 因为EF CE ⊥,CD CE C =,,CD CE ⊂平面CDE ,所以EF ⊥平面CDE .(2)如图所示,以点C 为坐标原点,以CB 、CF 和CD 所在直线分别为x 轴、y 轴和z 轴建立空间直角坐标系.过点E 作EG CF ⊥于点G .在Rt EFG中,EG AD ==EF =1FG =.因为CE EF ⊥,则90EFC ECF BCE ∠=︒-∠=∠,所以Rt EFG Rt ECB △△,EG GF EF BE BC EC==,所以2,BE CE == 所以2CG =,所以3CF =.设AB a ,则()0,0,0C,)A a,)E ,()0,3,0F .()0,2,AE a =-,()EF =-,()2,2,0CE =, 设平面AEF 的法向量(),,n x y z =.则00n AE n EF ⎧⋅=⎨⋅=⎩,即200y az y -=⎧⎪⎨+=⎪⎩, 令2z=,得,2n a ⎫=⎪⎭.因为CD ⊥平面EFC ,()0,0,CD a =,所以1cos ,2n CD ==,解得a =所以当AB =A EF C --的大小为60°.【名师点睛】本题考查空间向量法求二面角.求空间角的方法:(1)几何法(定义法):根据定义作出二面角的平面角并证明,然后解三角形得出结论; (2)空间向量法:建立空间直角坐标系,写出各点为坐标,求出平面的法向量,由两个平面法向量的夹角得二面角(它们相等或互补).23.如图,四棱锥E ABCD -中,底面ABCD 为直角梯形,其中AB BC ⊥,//CD AB ,面ABE ⊥面ABCD ,且224AB AE BE BC CD =====,点M 在棱AE 上.(1)证明:当2MA EM =时,直线//CE 平面BDM ;(2)当AE ⊥平面MBC 时,求二面角E BD M --的余弦值.【试题来源】内蒙古赤峰市2021届高三模拟考试(理)【答案】(1)证明见解析;(2. 【解析】(1)连结BD 与AC 交于点N ,连结MN ,//AB CD ,24AB CD ==, CND ANB ∴△∽△,12CD CN AB AN ∴==, 12EM MA =,EM CN MA AN∴=,MN //EC ∴, 又MN ⊂面BDM ,CE ⊂面BDM ,//CE ∴平面BDM .(2)AE 平面MBC ,AE BM ∴⊥,M ∴是AE 的中点,取AB 的中点为O , OE ∴⊥平面ABCD ,以OD ,OA ,OE 所在的直线为x ,y ,z 轴建立空间直角坐标系O xyz -,则(0,2,0)B-,E ,(2,0,0)D ,(0,2,0)A ,M ,设平面EBD 的法向量为()1111,,x n y z=,则1111112200020x y n BD n BE y ⎧+=⎧⋅=⎪⎪⇒⎨⎨⋅=+=⎪⎪⎩⎩, 令11z =,则1y=1x =1(3,3,1)n ∴=-,设平面BDM 的法向量为()2222,,n x y z =,则2222222200030x y n BD n BM y ⎧+=⎧⋅=⎪⎪⇒⎨⎨⋅==⎪⎪⎩⎩,令2z 21y =-,21x =,1(1,13)n ∴=-, 1212123105cos ,||n n n n n n ⋅∴<>===⋅ ∴二面角E BD M --的余弦值为35. 24.已知正方体1111ABCD A B C D -,棱长为2,M 为棱CD 的中点,N 为面对角线1BC 的中点,如图.(1)求证:ND AN ⊥;(2)求平面1AMD 与平面11AAC C 所成锐二面角的余弦值.【试题来源】安徽省池州市2020-2021学年高三上学期期末(理)【答案】(1)证明见解析;(2 【解析】(1)取BC 的中点分别为F ,连接NF ,DF ,因为N ,F 分别为1BC ,BC 的中点,1111ABCD A B C D -是正方体,易得NF ⊥平面ABCD ,所以NF AM ⊥;因为FC MD =,AD DC =,FCD MDA ∠=∠,所以FCD MDA ≌△△,所以CFD DMA ∠=∠,所以90FDC DMA ∠+∠=︒,所以FD AM ⊥,因为NF FD F =,NF ⊂平面NFD ,FD ⊂平面NFD ,所以AM ⊥平面NFD , 又DN ⊂平面NFD ,所以ND AM ⊥;(2)以A 为原点,分别以AB 、AD 、1AA 方向为x 轴、y 轴、z 轴正方向,建立如下图所示空间直角坐标系:连接BD ,1C D ,在正方体1111ABCD A B C D -中,易知1BD C D =,且N 为1BC 中点,所以1DN BC ⊥.又11//BC AD ,所以1AD DN ⊥. 因为1AD AM A =,1AD ⊂平面1AMD ,AM ⊂平面1AMD ,所以ND ⊥平面1AMD ,故ND 为平面1AMD 的一个法向量;由1111ABCD A B C D -是正方体,得BD ⊥平面11AAC C ,故BD 为平面11AAC C 的一个法向量,因为()2,0,0B ,()0,2,0D ,()2,1,1N , 所以()2,1,1ND =--,()2,2,0BD =-, 所以(cos ,ND BDND BD ND BD -⋅<>===⋅则平面1AMD 与平面11AAC C25.如图,正方形ADEF 与梯形ABCD 所在的平面互相垂直,AD CD ⊥,AB ∥CD ,122AB AD CD ===,点M 在线段EC 上.(1)当点M 为EC 中点时,求证:BM ∥平面ADEF ;(2)当平面BDM 与平面ABFM 在线段EC 上的位置.【试题来源】宁夏固原市第五中学2021届高三年级期末考试(理)【答案】(1)证明见解析;(2)点M 为EC 中点.【解析】(1)以直线DA 、DC 、DE 分别为x 轴、y 轴、z 轴建立空间直角坐标系,则(2,0,0)A ,(2,2,0)B ,(0,4,0)C ,(0,0,2)E ,所以(0,2,1)M .所以(2,0,1)BM =-, 又(0,4,0)DC =是平面ADEF 的一个法向量.因为0BM DC ⋅=即BM DC ⊥,BM ⊄平面ADEF ,所以BM ∥平面ADEF ;(2)设(,,)M x y z ,则(,,2)EM x y z =-,又(0,4,2)EC =-,设()01EM EC λλ=≤≤,则0,4,22x y z λλ===-,即(0,4,22)M λλ-.设111(,,)n x y z =是平面BDM 的一个法向量,则11112204(22)0DB n x y DM n y z λλ⎧⋅=+=⎪⎨⋅=+-=⎪⎩,取11x =得11y =-,此时显然1λ=时不符合,则121z λλ=-,即2(1,1,)1n λλ=--, 又由题设,(2,0,0)DA =是平面ABF 的一个法向量,所以cos ,622DA n DA n DA n ⋅===⋅,解得12λ=,即点M 为EC 中点. 【名师点睛】利用法向量求解空间面面角的关键在于“四破”:第一,破“建系关”,构建恰当的空间直角坐标系;第二,破“求坐标关”,准确求解相关点的坐标;第三,破“求法向量关”,求出平面的法向量;第四,破“应用公式关”.26.如图所示,在多面体ABCDEF 中,//AB CD ,AB BC ⊥,22AB BC CD ==,四边形ADEF 为矩形,平面ADEF ⊥平面ABCD ,AF AB λ=.(1)证明://DF 平面BCE ;(2)若二面角C BE F --λ的值. 【试题来源】江西宜春市2021届高三上学期数学(理)期末试题【答案】(1)证明见解析;(2)1.【解析】(1)取AB 的中点为M ,连接FM CM DM ,,,因为//AM CD 且AM CD =,四边形AMCD 为平行四边形,所以//AD MC 且AD MC =,因为四边形ADEF 为矩形,所以//FE MC 且=FEMC ,所以四边形EFMC 是平行四边形,所以//FM EC ,且EC ⊂平面BEC ,FM ⊄平面BEC ,。
专题15 复数的四则运算(解析版)
专题15 复数的四则运算一、单选题1.若复数Z 满足()·1 2z i i -=(i 是虚数部位),则下列说法正确的是 A .z 的虚部是-i B .Z 是实数C .z =D .2z z i +=【试题来源】江苏省盐城市滨海中学2020-2021学年高三上学期迎八省联考考前热身 【答案】C【分析】首先根据题意化简得到1z i =-,再依次判断选项即可.【解析】()()()22122211112i i i i iz i i i i ++====---+-. 对选项A ,z 的虚部是1-,故A 错误. 对选项B ,1z i =-为虚数,故B 错误.对选项C ,z ==C 正确.对选项D ,112z z i i +=-++=,故D 错误.故选C 2.已知复数1z i =+(i 为虚数单位),则1z在复平面内对应的点在 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】安徽省六安市示范高中2020-2021学年高三上学期教学质量检测(文) 【答案】D【分析】由复数的运算化简1z,再判断复平面内对应的点所在象限. 【解析】因为()()11111122i i z i i -==-+-,所以1z 在复平面内对应的点11 ,22⎛⎫- ⎪⎝⎭在第四象限.故选D3.已知复数1z i =+(i 为虚数单位),则1z在复平面内对应的点在 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】安徽省六安市示范高中2020-2021学年高三上学期教学质量检测(理)【答案】D 【分析】化简复数1z,利用复数的几何意义可得出结论. 【解析】因为()()11111112i i z i i i --===++-,所以1z在复平面内对应的点的坐标为11,22⎛⎫- ⎪⎝⎭,在第四象限.故选D . 4.设复数z 满足11zi z+=-,则z = A .i B .i - C .1D .1i +【试题来源】山东省威海市2020-2021学年高三上学期期末 【答案】B【分析】利用除法法则求出z ,再求出其共轭复数即可【解析】11zi z+=-得()11z i z +=-,即()()()()111111i i i z i i i i ---===++-,z i =-,故选B. 5.(1)(4)i i -+= A .35i + B .35i - C .53i +D .53i -【试题来源】安徽省皖西南联盟2020-2021学年高三上学期期末(文) 【答案】D【分析】根据复数的乘法公式,计算结果.【解析】2(1)(4)4453i i i i i i -+=-+-=-.故选D 6.设复数z 满足()11z i i -=+,则z 的虚部为. A .1- B .1 C .iD .i -【试题来源】安徽省芜湖市2020-2021学年高三上学期期末(文) 【答案】B【分析】利用复数的除法化简复数z ,由此可得出复数z 的虚部.【解析】()11z i i -=+,()()()211111i iz i i i i ++∴===--+, 因此,复数z 的虚部为1.故选B . 7.若复数z 满足21zi i=+,则z = A .22i + B .22i - C .22i --D .22i -+【试题来源】安徽省芜湖市2020-2021学年高三上学期期末(理) 【答案】C【分析】求出()2122z i i i =+=-+,再求解z 即可. 【解析】()2122z i i i =+=-+,故22z i =--,故选C. 8.将下列各式的运算结果在复平面中表示,在第四象限的为A .1ii + B .1ii +- C .1i i-D .1i i--【试题来源】河南省湘豫名校2020-2021学年高三上学期1月月考(文) 【答案】A【分析】对A 、B 、C 、D 四个选项分别化简,可得. 【解析】由11ii i+=-在第四象限.故选A . 【名师点睛】(1)复数的代数形式的运算主要有加、减、乘、除及求低次方根; (2)复数除法实际上是分母实数化的过程.9.若复数z 满足()z 1i i +=- (其中i 为虚数单位)则复数z 的虚部为A .12-B .12C .12i -D .12i【试题来源】安徽省马鞍山市2020-2021学年高三上学期第一次教学质量监测(文) 【答案】A【分析】先由已知条件利用复数的除法运算求出复数z ,再求其虚部即可. 【解析】由()z 1i i +=-可得()()()111111222i i i z i i i ----===--+-,所以复数z 的虚部为12-,故选A 10.复数z 满足()212()z i i -⋅+=(i 为虚数单位),则复数z 在复平面内对应的点在 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】宁夏吴忠市2021届高三一轮联考(文) 【答案】D【分析】先计算复数221z i i=++,再求其共轭复数,即可求出共轭复数对应的点,进而可得在复平面内对应的点所在的象限. 【解析】由()()212z i i -⋅+=得()()()()21212211112i i z i i i i i ---====-++-, 所以1z i =+,1z i =-.所以复数z 在复平面内对应的点为()1,1-, 位于第四象限,故选D .11.已知复数z 满足(2)z i i -=(i 为虚数单位),则z = A .125i-+ B .125i-- C .125i- D .125i+ 【试题来源】安徽省名校2020-2021学年高三上学期期末联考(文) 【答案】A【分析】由已知可得2iz i=-,再根据复数的除法运算可得答案. 【解析】因为(2)z i i -=,所以()()()2122225i i i i z i i i +-+===--+.故选A . 12.已知复数3iz i-=,则z =A .4 BCD .2【试题来源】江西省吉安市“省重点中学五校协作体”2021届高三第一次联考(文) 【答案】B【分析】利用复数代数形式的乘除运算化简,再由复数模的计算公式求解. 【解析】因为()()()3331131i i i i z i i i i -⋅----====--⋅-,所以z ==B .【名师点睛】本题考查复数代数形式的乘除运算,考查复数模的求法,属于基础题. 13.复数z 满足:()11i z i -=+,其中i 为虚数单位,则z 的共轭复数在复平面对应的点的坐标为 A .0,1 B .0,1 C .1,0D .()1,0【试题来源】江西宜春市2021届高三上学期数学(理)期末试题 【答案】A【分析】先由()11i z i -=+求出复数z ,从而可求出其共轭复数,进而可得答案【解析】由()11i z i -=+,得21i (1i)2ii 1i (1i)(1+i)2z ++====--, 所以z i =-,所以其在复平面对应的点为0,1,故选A 14.已知复数312iz i+=-,则z =A .1 BCD .2【试题来源】湖南省岳阳市平江县第一中学2020-2021学年高二上学期1月阶段性检测 【答案】B【分析】利用复数的除法法则化简复数z ,利用复数的模长公式可求得z .【解析】()()()()2312337217121212555i i i i i z i i i i +++++====+--+,因此,z ==B . 15.设复1iz i=+(其中i 为虚数单位),则复数z 在复平面内对应的点位于A .第一象限B .第二象限C .第三象限D .第四象限【试题来源】江苏省南通市如皋市2020-2021学年高三上学期期末 【答案】A【分析】利用复数的除法化简复数z ,利用复数的几何意义可得出结论. 【解析】()()()1111111222i i i i z i i i i -+====+++-,因此,复数z 在复平面内对应的点位于第一象限.故选A .16.已知(1)35z i i +=-,则z = A .14i - B .14i -- C .14i -+D .14i +【试题来源】江苏省盐城市一中、大丰高级中学等四校2020-2021学年高二上学期期末联考 【答案】B【分析】由复数的除法求解.【解析】由题意235(35)(1)3355141(1)(1)2i i i i i i z i i i i -----+====--++-.故选B 17.复数(2)i i +的实部为 A .1- B .1 C .2-D .2【试题来源】浙江省绍兴市上虞区2020-2021学年高三上学期期末 【答案】A【分析】将(2)i i +化简即可求解.【解析】(2)12i i i +=-+的实部为1-,故选A .18.已知i 是虚数单位,(1)2z i i +=,则复数z 所对应的点位于 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】山东省德州市2019-2020学年高一下学期期末 【答案】D【分析】利用复数的运算法则求解复数z ,再利用共轭复数的性质求z ,进而确定z 所对应的点的位置.【解析】由(1)2z i i +=,得()()()()2121211112i i i i z i i i i -+====+++-, 所以1z i =-,所以复数z 所对应的点为()1,1-,在第四象限,故选D .【名师点睛】对于复数的乘法,类似于多项式的四则运算,可将含有虚数单位i 的看作一类同类项,不含i 的看作另一类同类项,分别合并即可;对于复数的除法,关键是分子分母同乘以分母的共轭复数,解题中要注意把i 的幂写成最简形式. 19.若复数2iz i=+,其中i 为虚数单位,则z =A B C .25D .15【试题来源】重庆市南开中学2020-2021学年高二上学期期末 【答案】B【分析】先利用复数的除法运算法则化简复数2iz i=+,再利用复数模的公式求解即可. 【解析】因为()()()21212222555i i i i z i i i i -+====+++-,所以z ==,故选B . 20.52i i-= A .152i--B .52i-- C .152i- D .152i+ 【试题来源】江西省吉安市2021届高三上学期期末(文) 【答案】A【分析】根据复数的除法的运算法则,准确运算,即可求解. 【解析】由复数的运算法则,可得()5515222i i i ii i i ----==⨯.故选A .21.设复数z 满足()1z i i R +-∈,则z 的虚部为 A .1 B .-1 C .iD .i -【试题来源】湖北省2020-2021学年高三上学期高考模拟演练 【答案】B【分析】根据复数的运算,化简得到()11(1)z i i a b i +-=+++,根据题意,求得1b =-,即可求得z 的虚部,得到答案.【解析】设复数,(,)z a bi a b R =+∈,则()11(1)z i i a b i +-=+++,因为()1z i i R +-∈,可得10b +=,解得1b =-,所以复数z 的虚部为1-.故选B . 22.若复数151iz i-+=+,其中i 为虚数单位,则z 的虚部是 A .3 B .3- C .2D .2-【试题来源】安徽省淮南市2020-2021学年高三上学期第一次模拟(文) 【答案】A【分析】先利用复数的除法运算,化简复数z ,再利用复数的概念求解.【解析】因为复数()()()()1511523111i i i z i i i i -+--+===+++-, 所以z 的虚部是3,故选A. 23.若m n R ∈、且4334im ni i+=+-(其中i 为虚数单位),则m n -= A .125- B .1- C .1D .0【试题来源】湖北省部分重点中学2020-2021学年高三上学期期末联考 【答案】B【分析】对已知进行化简,根据复数相等可得答案.【解析】因为()()()()433443121225343434916i i i ii m ni i i i +++-+====+--++, 根据复数相等,所以0,1m n ==,所以011m n -=-=-.故选B .24.若复数z满足()36z =-(i 是虚数单位),则复数z =A.32-B.32- C.322+D.322-- 【试题来源】湖北省荆州中学2020-2021学年高二上学期期末 【答案】A【分析】由()36z =-,得z =,利用复数除法运算法则即可得到结果.【解析】复数z满足()36z +=-,6332z --=====-∴+,故选A .25.若复数2i()2i+=∈-R a z a 是纯虚数,则z = A .2i - B .2i C .i -D .i【试题来源】河南省驻马店市2020-2021学年高三上学期期末考试(理) 【答案】D【分析】由复数的除法运算和复数的分类可得结果. 【解析】因为2i (2i)(2i)22(4)i2i (2i)(2i)5+++-++===-+-a a a a z 是纯虚数, 所以22040a a -=⎧⎨+≠⎩,则1a =,i =z .故选D .26.复数12z i =+,213z i =-,其中i 为虚数单位,则12z z z =⋅在复平面内的对应点位于 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】江苏省G4(苏州中学、常州中学、盐城中学、扬州中学)2020-2021学年高三上学期期末联考 【答案】D【分析】根据复数的乘法法则,求得55z i =-,即可求得答案. 【解析】由题意得122(2)(13)25355i i i i i z z z =+-=-==--⋅, 所以12z z z =⋅在复平面内的对应点为(5,-5)位于第四象限,故选D27.复数2()2+∈-R a ia i 的虚部为 A .225+aB .45a - C .225a -D .45a +【试题来源】河南省驻马店市2020-2021学年高三上学期期末考试(文) 【答案】D【分析】由得数除法运算化为代数形式后可得. 【解析】因为2i (2i)(2i)22(4)i 2i (2i)(2i)5+++-++==-+-a a a a ,所以其虚部为45a +.故选D . 28.复数z 满足()12z i i ⋅+=,则2z i -=ABCD .2【试题来源】安徽省蚌埠市2020-2021学年高三上学期第二次教学质量检查(文) 【答案】A【分析】先利用除法化简计算z ,然后代入模长公式计算.【解析】()1i 2i z ⋅+=变形得22222221112-+====++-i i i i z i i i ,所以2121-=+-=-==z i i i i A .29.i 是虚数单位,若()17,2ia bi ab R i-=+∈+,则ab 的值是 A .15- B .3- C .3D .15【试题来源】山东省菏泽市2020-2021学年高三上学期期末 【答案】C【分析】根据复数除法法则化简得数后,由复数相等的定义得出,a b ,即可得结论.【解析】17(17)(2)2147132(2)(2)5i i i i i i i i i ------===--++-, 所以1,3a b =-=-,3ab =.故选C . 30.复数3121iz i -=+的虚部为 A .12i -B .12i C .12-D .12【试题来源】江西省赣州市2021届高三上学期期末考试(理) 【答案】C【分析】由复数的乘除法运算法则化简为代数形式,然后可得虚部.【解析】231212(12)(1)1223111(1)(1)222i i i i i i i z i i i i i ---++--=====-+--+, 虚部为12-.故选C . 31.若复数z 满足(1)2i z i -=,i 是虚数单位,则z z ⋅=AB .2C .12D .2【试题来源】内蒙古赤峰市2021届高三模拟考试(理) 【答案】B【分析】由除法法则求出z ,再由乘法法则计算.【解析】由题意222(1)2()11(1)(1)2i i i i i z i i i i ++====-+--+, 所以(1)(1)2z z i i ⋅=-+--=.故选B . 32.若23z z i +=-,则||z =A .1 BCD .2【试题来源】河南省(天一)大联考2020-2021学年高三上学期期末考试(理) 【答案】B【分析】设(,)z a bi a b R =+∈,代入已知等式求得,a b 后再由得数的模的定义计算. 【解析】设(,)z a bi a b R =+∈,则22()33z z a bi a bi a bi i +=++-=-=-,所以以331a b =⎧⎨-=-⎩,解得11a b =⎧⎨=⎩,所以==z B .33.复数z 满足(2)(1)2z i i -⋅+=(i 为虚数单位),则z = A .1 B .2CD 【试题来源】宁夏吴忠市2021届高三一轮联考(理) 【答案】C【分析】先将复数化成z a bi =+形式,再求模. 【解析】由(2)(1)2z i i -⋅+=得2211z i i i-==-+,所以1z i =+,z ==C .34.已知a R ∈,若()()224ai a i i +-=-(i 为虚数单位),则a = A .-1 B .0 C .1D .2【试题来源】浙江省杭州市2020-2021学年高三上学期期末教学质量检测 【答案】B【分析】将()()22ai a i +-展开可得答案.【解析】()()()222444ai a i a a i i +-=+-=-,所以0a =,故选B.35.已知i 为虚数单位,且复数3412ii z+=-,则复数z 的共轭复数为 A .12i -+ B .12i -- C .12i +D .1 2i -【试题来源】湖北省孝感市应城市第一高级中学2020-2021学年高二上学期期末【答案】D【分析】根据复数模的计算公式,以及复数的除法运算,求出z ,即可得出其共轭复数. 【解析】因为3412i i z+=-,所以512z i =-,则()()()512512121212i z i i i i +===+--+, 因此复数z 的共轭复数为1 2i -.故选D . 36.已知复数i()1ia z a +=∈+R 是纯虚数,则z 的值为 A .1 B .2 C .12D .-1【试题来源】江西省赣州市2021届高三上学期期末考试(文) 【答案】A【分析】根据复数除法运算化简z ,根据纯虚数定义求得a ,再求模长. 【解析】()()()()11121122a i i a i a a z i i i i +-++-===+++-是纯虚数,102102a a +⎧=⎪⎪∴⎨-⎪≠⎪⎩,解得1a =-,所以z i ,1z =.故选A . 37.设复数11iz i,那么在复平面内复数31z -对应的点位于 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】陕西省咸阳市2020-2021学年高三上学期高考模拟检测(一)(理) 【答案】C【分析】利用复数的除法法则化简复数z ,再将复数31z -化为一般形式,即可得出结论.【解析】()()()21121112i ii z i i i i ---====-++-,3113z i ∴-=--, 因此,复数31z -在复平面内对应的点位于第三象限.故选C . 38.已知复数13iz i-=+(i 为虚数单位),则z 在复平面内对应的点位于 A .第一象限B .第二象限C .第三象限D .第四象限【试题来源】江西省南昌市新建区第一中学2020-2021学年高二上学期期末考试(理) 【答案】D【分析】将复数化简成z a bi =+形式,则在复平面内对应的点的坐标为(),a b ,从而得到答案.【解析】因为1(1)(3)24123(3)(3)1055i i i i z i i i i ----====-++-, 所以z 在复平面内对应的点12(,)55-位于第四象限,故选D.39.若复数2(1)34i z i+=+,则z =A .45 B .35C .25D 【试题来源】成都市蓉城名校联盟2020-2021学年高三上学期(2018级)第二次联考 【答案】C 【分析】先求出8625iz -=,再求出||z 得解. 【解析】由题得()()()()212342863434343425i i i i iz i i i i +-+====+++-,所以102255z ===.故选C. 40.设复数11iz i,那么在复平面内复数1z -对应的点位于 A .第一象限 B .第二象限 C .第三象限D .第四象限【试题来源】陕西省咸阳市2020-2021学年高三上学期高考模拟检测(一)(文) 【答案】C【分析】先求出z i =-,11z i -=--,即得解.【解析】由题得21(1)21(1)(1)2i i iz i i i i ---====-++-, 所以11z i -=--,它对应的点的坐标为(1,1)--, 所以在复平面内复数1z -对应的点位于第三象限.故选C. 二、多选题1.已知m ∈R ,若6()64m mi i +=-,则m =A .B .1-CD .1【试题来源】2021年高考一轮数学(理)单元复习一遍过 【答案】AC【分析】将6()m mi +直接展开运算即可.【解析】因为()()66661864m mi m i im i +=+=-=-,所以68m =,所以m =故选AC . 2.设复数z 满足1z i z+=,则下列说法错误的是 A .z 为纯虚数B .z 的虚部为12i -C .在复平面内,z 对应的点位于第三象限D .2z = 【试题来源】2021年新高考数学一轮复习学与练 【答案】AB【分析】先由复数除法运算可得1122z i =--,再逐一分析选项,即可得答案. 【解析】由题意得1z zi +=,即111122z i i -==---, 所以z 不是纯虚数,故A 错误;复数z 的虚部为12-,故B 错误;在复平面内,z 对应的点为11(,)22--,在第三象限,故C 正确;2z ==,故D 正确.故选AB 【名师点睛】本题考查复数的除法运算,纯虚数、虚部的概念,复平面内点所在象限、复数求模的运算等知识,考查计算求值的能力,属基础题.3.已知复数122z =-,则下列结论正确的有 A .1z z ⋅=B .2z z =C .31z =-D .202012z =-+ 【试题来源】山东新高考质量测评联盟2020-2021学年高三上学期10月联考 【答案】ACD【分析】分别计算各选项的值,然后判断是否正确,计算D 选项的时候注意利用复数乘方的性质.【解析】因为111312244z z ⎛⎫⎛⎫-+=+= ⎪⎪⎪⎪⎝⎭⎭=⎝⋅,所以A 正确;因为221122z ⎛⎫=-⎪⎪⎝⎭=,122z =+,所以2z z ≠,所以B 错误;因为3211122z z z ⎛⎫⎛⎫=⋅=-=- ⎪⎪ ⎪⎪⎝⎭⎝⎭,所以C 正确;因为6331z z z =⋅=,所以()202063364431112222zzz z z ⨯+⎛⎫===⋅=-⋅-=-+ ⎪ ⎪⎝⎭,所以D 正确,故选ACD .【名师点睛】本题考查复数乘法与乘方的计算,其中还涉及到了共轭复数的计算,难度较易. 4.下面是关于复数21iz =-+的四个命题,其中真命题是A .||z =B .22z i =C .z 的共轭复数为1i -+D .z 的虚部为1-【试题来源】福建省龙海市第二中学2019-2020学年高二下学期期末考试 【答案】ABCD【分析】先根据复数的除法运算计算出z ,再依次判断各选项. 【解析】()()()2121111i z i i i i --===---+-+--,z ∴==,故A 正确;()2212z i i =--=,故B 正确;z 的共轭复数为1i -+,故C 正确;z 的虚部为1-,故D 正确;故选ABCD .【名师点睛】本题考查复数的除法运算,以及对复数概念的理解,属于基础题. 5.若复数351iz i-=-,则A .z =B .z 的实部与虚部之差为3C .4z i =+D .z 在复平面内对应的点位于第四象限 【试题来源】2021年新高考数学一轮复习学与练 【答案】AD【分析】根据复数的运算先求出复数z ,再根据定义、模、几何意义即可求出. 【解析】()()()()351358241112i i i iz i i i i -+--====---+,z ∴==,z 的实部为4,虚部为1-,则相差5,z 对应的坐标为()41-,,故z 在复平面内对应的点位于第四象限,所以AD 正确,故选AD .6.已知复数202011i z i+=-(i 为虚数单位),则下列说法错误的是A .z 的实部为2B .z 的虚部为1C .z i =D .||z =【试题来源】2021年新高考数学一轮复习学与练 【答案】AC【分析】根据复数的运算及复数的概念即可求解.【解析】因为复数2020450511()22(1)11112i i i z i i i i +++=====+---,所以z 的虚部为1,||z =,故AC 错误,BD 正确.故选AC. 7.已知复数cos sin 22z i ππθθθ⎛⎫=+-<< ⎪⎝⎭(其中i 为虚数单位)下列说法正确的是A .复数z 在复平面上对应的点可能落在第二象限B .z 可能为实数C .1z =D .1z的虚部为sin θ 【试题来源】湖北省六校(恩施高中、郧阳中学、沙市中学、十堰一中、随州二中、襄阳三中)2020-2021学年高三上学期11月联考 【答案】BC【分析】分02θπ-<<、0θ=、02πθ<<三种情况讨论,可判断AB 选项的正误;利用复数的模长公式可判断C 选项的正误;化简复数1z,利用复数的概念可判断D 选项的正误.【解析】对于AB 选项,当02θπ-<<时,cos 0θ>,sin 0θ<,此时复数z 在复平面内的点在第四象限;当0θ=时,1z R =-∈; 当02πθ<<时,cos 0θ>,sin 0θ>,此时复数z 在复平面内的点在第一象限.A 选项错误,B 选项正确; 对于C 选项,22cos sin 1z θθ=+=,C 选项正确;对于D 选项,()()11cos sin cos sin cos sin cos sin cos sin i i z i i i θθθθθθθθθθ-===-++⋅-, 所以,复数1z的虚部为sin θ-,D 选项错误.故选BC . 8.已知非零复数1z ,2z 满足12z z R ∈,则下列判断一定正确的是 A .12z z R +∈B .12z z R ∈C .12z R z ∈D .12z R z ∈【试题来源】重庆市南开中学2020-2021学年高二上学期期中 【答案】BD【分析】设12,(,,,)z a bi z c di a b c d R =+=+∈,结合选项逐个计算、判定,即可求解. 【解析】设12,(,,,)z a bi z c di a b c d R =+=+∈,则()()12()()z z a bi c di ac bd ad bc i =++=-++,则0ad bc +=,对于A 中,12()()z z a bi c di a c b d i +=+++=+++,则12z z R +∈不一定成立,所以不正确;对于B 中,12()()ac bd ad bc z R i z =-+∈-一定成立,所以B 正确; 对于C 中,()()()()2122()()a bi c di a bi ac bd ad bc i R c di c di c z di z c d+-++--==∈++-+=不一定成立,所以不正确;对于D 中,()()()()2122()()a bi c di a bi ac bd ad bc iR c di c di c z di z c d ++++++==∈--++=一定成立,所以正确.故选BD .9.已知复数()()()32=-+∈z a i i a R 的实部为1-,则下列说法正确的是 A .复数z 的虚部为5- B .复数z 的共轭复数15=-z i C.z =D .z 在复平面内对应的点位于第三象限【试题来源】辽宁省六校2020-2021学年高三上学期期中联考 【答案】ACD【分析】首先化简复数z ,根据实部为-1,求a ,再根据复数的概念,判断选项. 【解析】()()()()23232323223z a i i a ai i i a a i =-+=+--=++-,因为复数的实部是-1,所以321a +=-,解得1a =-, 所以15z i =--,A .复数z 的虚部是-5,正确;B .复数z 的共轭复数15z i =-+,不正确;C .z ==D .z 在复平面内对应的点是()1,5--,位于第三象限,正确.故选ACD 10.已知复数cos sin 22z i ππθθθ⎛⎫=+-<< ⎪⎝⎭(其中i 为虚数单位),下列说法正确的是() A .复数z 在复平面上对应的点可能落在第二象限 B .cos z θ=C .1z z ⋅=D .1z z+为实数 【试题来源】山东省菏泽市2021届第一学期高三期中考试数学(B )试题 【答案】CD【分析】利用复数对应点,结合三角函数值的范围判断A ;复数的模判断B ;复数的乘法判断C ;复数的解法与除法,判断D . 【解析】复数cos sin ()22z i ππθθθ=+-<<(其中i 为虚数单位),复数z 在复平面上对应的点(cos ,sin )θθ不可能落在第二象限,所以A 不正确;1z ==,所以B 不正确;22·(cos sin )(cos sin )cos sin 1z z i i θθθθθθ=+-=+=.所以C 正确;11cos sin cos sin cos()sin()2cos cos sin z i i i z i θθθθθθθθθ+=++=++-+-=+为实数,所以D 正确;故选CD11.已知i 为虚数单位,下面四个命题中是真命题的是 A .342i i +>+B .24(2)()a a i a R -++∈为纯虚数的充要条件为2a =C .()2(1)12z i i =++的共轭复数对应的点为第三象限内的点D .12i z i +=+的虚部为15i 【试题来源】2020-2021年新高考高中数学一轮复习对点练 【答案】BC【分析】根据复数的相关概念可判断A ,B 是否正确,将()2(1)12z i i =++展开化简可判断C 选项是否正确;利用复数的除法法则化简12iz i+=+,判断D 选项是否正确. 【解析】对于A ,因为虚数不能比较大小,故A 错误;对于B ,若()242a a i ++-为纯虚数,则24020a a ⎧-=⎨+≠⎩,解得2a =,故B 正确;对于C ,()()()211221242z i i i i i =++=+=-+,所以42z i =--对应的点为()4,2--位于第三象限内,故C 正确;对于D ,()()()()12132225i i i i z i i i +-++===++-,虚部为15,故D 错误.故选BC . 12.已知复数(12)5z i i +=,则下列结论正确的是A .|z |B .复数z 在复平面内对应的点在第二象限C .2z i =-+D .234z i =+【试题来源】河北省邯郸市2021届高三上学期期末质量检测【答案】AD【分析】利用复数的四则运算可得2z i =+,再由复数的几何意义以及复数模的运算即可求解.【解析】5512122121212()()()()i i i z i i i i i i -===-=+++-,22,||34z i z z i =-==+ 复数z 在复平面内对应的点在第一象限,故AD 正确.故选AD13.已知i 是虚数单位,复数12i z i -=(z 的共轭复数为z ),则下列说法中正确的是 A .z 的虚部为1B .3z z ⋅=C .z =D .4z z +=【试题来源】山东省山东师大附中2019-2020学年高一下学期5月月考【答案】AC 【分析】利用复数的乘法运算求出122i z i i-==--,再根据复数的概念、复数的运算以及复数模的求法即可求解. 【解析】()()()12122i i i z i i i i ---===---,所以2z i =-+, 对于A ,z 的虚部为1,故A 正确;对于B ,()2225z z i ⋅=--=,故B 不正确;对于C ,z =C 正确;对于D ,4z z +=-,故D 不正确.故选AC14.早在古巴比伦时期,人们就会解一元二次方程.16世纪上半叶,数学家得到了一元三次、一元四次方程的解法.此后数学家发现一元n 次方程有n 个复数根(重根按重数计).下列选项中属于方程310z -=的根的是A.12 B.12-+ C.122-- D .1【试题来源】江苏省苏州市2020-2021学年高二上学期1月学业质量阳光指标调研【答案】BCD【分析】逐项代入验证是否满足310z -=即可.【解析】对A,当122z =+时, 31z -31122i ⎛⎫+- ⎪ ⎪⎭=⎝21112222⎛⎫⎛⎫+⋅+- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭=21121344i ⎛⎫=++⋅ ⎪⎛⎫+- ⎪ ⎝ ⎭⎭⎪⎪⎝12112⎛⎫=-+⋅⎛⎫+- ⎪ ⎪⎝⎭⎪ ⎪⎝⎭2114⎫=-+-⎪⎪⎝⎭ 13144=--- 2=-,故3120z -=-≠,A 错误; 对B,当12z =-时,31z -3112⎛⎫-+- ⎪ ⎪⎝⎭=211122⎛⎫⎛⎫-⋅-- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭=2113124242i ⎛⎫=-+⋅ ⎪ ⎪⎛⎫-+- ⎪ ⎪⎝⎭⎝⎭1221122⎛⎫-⎛⎫=--⋅ ⎪+ - ⎪ ⎪⎝⎭⎪⎝⎭21142⎛⎫=-- ⎪ ⎪⎝⎭ 13144=+- 0=,故310z -=,B 正确; 对C,当12z =-时,31z-31122⎛⎫--- ⎪ ⎪⎝⎭=21112222⎛⎫⎛⎫--⋅--- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭=21131442i ⎛⎫=++⋅ ⎪ ⎪⎛⎫--- ⎪ ⎪⎝⎭⎝⎭12112⎛⎫-⎛⎫=-+⋅ ⎪- - ⎪ ⎪⎝⎭⎪⎝⎭2114⎫=--⎪⎪⎝⎭13144=+-0=,故310z -=,C 正确; 对D ,显然1z =时,满足31z =,故D 正确.故选BCD .15.已知复数()()122z i i =+-,z 为z 的共轭复数,则下列结论正确的是A .z 的虚部为3iB .5z =C .4z -为纯虚数D .z 在复平面上对应的点在第四象限【试题来源】湖南师范大学附属中学2020-2021学年高二上学期期末【答案】BCD【分析】先根据复数的乘法运算计算出z ,然后进行逐项判断即可.【解析】因为()()12243z i i i =+-=+,则z 的虚部为3,5z z ===,43z i -=为纯虚数,z 对应的点()4,3-在第四象限,故选BCD .三、填空题1.已知复数z 满足(1)1z i i ⋅-=+(i 为虚数单位),则z =_________.【试题来源】上海市松江区2021届高三上学期期末(一模)【答案】1【分析】把已知等式变形,利用复数代数形式的乘除运算化简,再由复数模的计算公式求解.【解析】由(1)1z i i ⋅-=+,得21(1)1(1)(1)i i z i i i i ++===--+,所以1z =.故答案为1. 2.i 是虚数单位,复数1312i i-+=+_________. 【试题来源】天津市七校2020-2021学年高三上学期期末联考【答案】1i +【分析】分子分母同时乘以分母的共轭复数12i -,再利用乘法运算法则计算即可. 【解析】()()()()22131213156551121212145i i i i i i i i i i i -+--+-+-+====+++--.故答案为1i +. 3.若复数z 满足方程240z +=,则z =_________.【试题来源】上海市复旦大学附属中学2020-2021学年高二上学期期末【答案】2i ±【分析】首先设z a bi =+,再计算2z ,根据实部和虚部的数值,列式求复数..【解析】设z a bi =+,则22224z a b abi =-+=-,则2240a b ab ⎧-=-⎨=⎩,解得02a b =⎧⎨=±⎩,所以2z i =±,故答案为2i ±. 4.复数21i-的虚部为_________. 【试题来源】上海市上海交通大学附属中学2020-2021学年高二上学期期末【答案】1【分析】根据分母实数化,将分子分母同乘以分母的共轭复数1i +,然后即可判断出复数的虚部. 【解析】因为()()()2121111i i i i i +==+--+,所以复数的虚部为1,故答案为1. 5.若复数z 满足(12)1i z i +=-,则复数z 的虚部为_________.【试题来源】山东省山东师大附中2019-2020学年高一下学期5月月考 【答案】35【分析】根据复数的除法运算法则,求出z ,即可得出结果.【解析】因为(12)1i z i +=-,所以()()()()112113213121212555i i i i z i i i i -----====--++-, 因此其虚部为35.故答案为35. 6.复数34i i+=_________. 【试题来源】北京市东城区2021届高三上学期期末考试【答案】43i -【分析】分子和分母同乘以分母的共轭复数,整理后得到最简形式即可. 【解析】由复数除法运算法则可得, ()343434431i i i i i i i i +⋅+-===-⋅-,故答案为43i -. 7.已知复数(1)z i i =⋅+,则||z =_________.【试题来源】北京市西城区2020-2021学年高二上学期期末考试【分析】根据复数的运算法则,化简复数为1z i =-+,进而求得复数的模,得到答案.【解析】由题意,复数(1)1z i i i =⋅+=-+,所以z == 8.i 是虚数单位,复数73i i-=+_________. 【试题来源】宁夏银川一中2020-2021学年高二上学期期末考试(文)【答案】2i -【分析】根据复数除法运算法则直接计算即可. 【解析】()()()()27372110233310i i i i i i i i i ----+===-++-.故答案为2i -. 9.设复数z 的共轭复数是z ,若复数143i z i -+=,2z t i =+,且12z z ⋅为实数,则实数t 的值为_________.【试题来源】宁夏银川一中2020-2021学年高二上学期期末考试(理) 【答案】34【分析】先求出12,z z ,再计算12z z ⋅即得解. 【解析】由题得14334i z i i-+==+,2z t i =-, 所以12(34)()34(43)z z i t i t t i ⋅=+-=++-为实数, 所以3430,4t t -=∴=.故答案为34【名师点睛】复数(,)a bi a b R +∈等价于0b =,不需要限制a .10.函数()n nf x i i -=⋅(n N ∈,i 是虚数单位)的值域可用集合表示为_________. 【试题来源】上海市上海中学2020-2021学年高二上学期期末【答案】{}1【分析】根据复数的运算性质可函数的值域.【解析】()()1111nn n n n n n n f x i i i i i i i i --⎛⎫=⋅⋅⋅⋅= ⎪⎝=⎭==,故答案为{}1. 11.已知()20212i z i +=(i 为虚数单位),则z =_________.【试题来源】河南省豫南九校2021届高三11月联考教学指导卷二(理)【分析】由i n 的周期性,计算出2021i i =,再求出z ,求出z .【解析】因为41i =,所以2021i i =,所以i 12i 2i 55z ==++,所以z z == 【名师点睛】复数的计算常见题型:(1) 复数的四则运算直接利用四则运算法则;(2) 求共轭复数是实部不变,虚部相反;(3) 复数的模的计算直接根据模的定义即可.12.若31z i =-(i 为虚数单位),则z 的虚部为_________. 【试题来源】江西省上饶市2021届高三第一次高考模拟考试(文) 【答案】32-【分析】利用复数的除法化简复数z ,由此可得出复数z 的虚部. 【解析】()()()313333111122i z i i i i i +==-=-=-----+,因此,复数z 的虚部为32-. 故答案为32-. 13.设i 为虚数单位,若复数z 满足()21z i -⋅=,则z =_________. 【试题来源】江西省上饶市2020-2021学年高二上学期期末(文)【答案】2i +【分析】利用复数的四则运算可求得z ,利用共轭复数的定义可求得复数z .【解析】()21z i -⋅=,122z i i ∴=+=-,因此,2z i =+.故答案为2i +. 14.已知i 是虚数单位,则11i i+=-_________. 【试题来源】湖北省宜昌市2020-2021学年高三上学期2月联考【答案】1【分析】利用复数的除法法则化简复数11i i +-,利用复数的模长公式可求得结果. 【解析】()()()21121112i i i i i i i ++===--+,因此,111i i i +==-.故答案为1. 15.i 是虚数单位,复数103i i=+____________. 【试题来源】天津市南开中学2020-2021学年高三上学期第四次月考【答案】13i +【分析】根据复数的除法运算算出答案即可.【解析】()()()()10310313333i i i i i i i i i -==-=+++-,故答案为13i +. 16.在复平面内,复数()z i a i =+对应的点在直线0x y +=上,则实数a =_________.【试题来源】北京市丰台区2021届高三上学期期末练习【答案】1【分析】由复数的运算法则和复数的几何意义直接计算即可得解.【解析】2()1z i a i ai i ai =+=+=-+,其在复平面内对应点的坐标为()1,a -, 由题意有:10a -+=,则1a =.故答案为1.17.已知复数z 满足()1234i z i +=+(i 为虚数单位),则复数z 的模为_________.【试题来源】江苏省苏州市2020-2021学年高二上学期1月学业质量阳光指标调研【分析】求出z 后可得复数z 的模.【解析】()()3412341121255i i i i z i +-+-===+,5z == 18.复数1i i-(i 是虚数单位)的虚部是_________. 【试题来源】北京通州区2021届高三上学期数学摸底(期末)考试【答案】1-【分析】先化简复数得1i 1i i-=--,进而得虚部是1-【解析】因为()()221i i 1i i i 1i i i--==--=--, 所以复数1i i-(i 是虚数单位)的虚部是1-.故答案为1-. 19.已知i 是虚数单位,复数11z i i =+-,则z =_________. 【试题来源】山东省青岛市2020-2021学年高三上学期期末【答案】2【分析】根据复数的除法运算,化简复数为1122z i =-+,再结合复数模的计算公式,即可求解. 【解析】由题意,复数()()111111122i z i i i i i i --=+=+=-+----,所以2z ==.故答案为2. 20.计算12z ==_______. 【试题来源】2021年高考一轮数学(理)单元复习一遍过【答案】-511【分析】利用复数的运算公式,化简求值.【解析】原式1212369100121511()i ==+=-+=--. 【名师点睛】本题考查复数的n次幂的运算,注意31122⎛⎫-+= ⎪ ⎪⎝⎭,()212i i +=, 以及()()612211i i ⎡⎤+=+⎣⎦,等公式化简求值. 四、双空题1.设32i i 1ia b =++(其中i 为虚数单位,a ,b ∈R ),则a =_________,b =_________. 【试题来源】浙江省绍兴市嵊州市2020-2021学年高三上学期期末【答案】1- 1- 【分析】利用复数的除法运算化简32i 1i 1i=--+,利用复数相等的定义得到a ,b 的值,即得解. 【解析】322(1)2211(1)(1)2i i i i i a bi i i i ----===--=+++-,1,1a b ∴=-=-. 故答案为-1;-1.2.已知k ∈Z , i 为虚数单位,复数z 满足:21k i z i =-,则当k 为奇数时,z =_________;当k ∈Z 时,|z +1+i |=_________.【试题来源】2020-2021学年【补习教材寒假作业】高二数学(苏教版)【答案】1i -+ 2【分析】由复数的运算及模的定义即可得解.【解析】当k 为奇数时,()()2211k k k i i ==-=-, 所以1z i -=-即1z i =-+,122z i i ++==; 当k 为偶数时,()()2211k k k i i ==-=,所以1z i =-,122z i ++==;所以12z i ++=.故答案为1i -+;2.3.若复数()211z m m i =-++为纯虚数,则实数m =_________,11z=+_________. 【试题来源】浙江省金华市义乌市2020-2021学年高三上学期第一次模拟考试【答案】1 1255i - 【分析】由题可得21010m m ⎧-=⎨+≠⎩,即可求出m ,再由复数的除法运算即可求出.【解析】复数()211z m m i =-++为纯虚数,21010m m ⎧-=∴⎨+≠⎩,解得1m =,。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
2021届江苏省G4(苏州中学、盐城中学、扬州中学、常州中学)
高三上学期1月期末调研考试
理科综合生物试卷
★祝考试顺利★
(含答案)
一、单项选择题:共 15题,每题2 分,共 30分。
每题只有一个选项最符合题意。
1. 下列关于细胞中化合物的叙述,错误的是()
A. 糖原、纤维素酶和脂肪酸的组成元素都主要是C、H、O
B. 细胞中合成淀粉、蛋白质及核酸的过程都会产生水
C. dATP可为DNA分子复制提供原料和能量
D. 通过“食盐补碘”可以有效预防“大脖子病”的发生
2. 下列有关利用传统发酵技术制作果酒、果醋及泡菜的叙述,正确的是()
A. 发酵原料和发酵装置都需进行灭菌,以防止杂菌污染
B. 发酵用菌种的细胞呼吸类型及生物膜系统的组成都是相同的
C. 三者的发酵液都主要是因为产生了大量二氧化碳而呈酸性
D. 制作泡菜时加入一定量的陈泡菜汁能加快发酵进程
3. 下图是细胞中内质网腔驻留蛋白逃逸及回收的示意图,其中途径1由内质网运输至高尔基体,途径 2则由高尔基体运输至内质网,通过KDEL受体的作用回收从内质网逃逸的驻留蛋白。
下列相关叙述正确的是()
A. 在内质网中,KDEL序列能与KDEL受体特异性结合
B. 细胞合成的蛋白质除部分经过途径2运输外,其他都要经过途径1运输
C. 胰高血糖素、抗体、消化酶等分泌蛋白上一般不存在KDEL 序列
D. 除图中所示囊泡的定向运输外,细胞中其他囊泡的运输方向则是随机的
4. 生物体结构与功能相统一的观点,既体现在细胞等生命系统水平上,也体现在分子水平上。
下列相关叙述错误的是()
A. 一个DNA上有多个复制起点,有利于细胞快速复制DNA
B. 一个mRNA上结合多个核糖体,有利于细胞快速合成多种蛋白质
C. 一种氨基酸对应多种密码子,有利于保证细胞翻译的速度
D. 双链DNA分子中GC含量增多,有利于增强其热稳定性
5. 下列有关高中生物实验操作的叙述,正确的是()
A. “绿叶中色素的提取和分离”实验中,用离心法对各种色素进行分离
B. “探究培养液中酵母菌种群数量的变化”实验中,用吸水纸引流让培养液充满血细胞计数板的计数室
C. “探究生长素类似物促进插条生根的最适浓度"实验中,正式实验时必须设置空白对照组
D. “观察根尖分生组织细胞的有丝分裂”实验中,需在高倍镜下观察细胞中染色体的存在状态
6. 下列有关赫尔希和蔡斯的T
噬菌体侵染大肠杵菌实验的叙述,正确的是()
2
A. 搅拌的目的是使大肠杆菌破裂,释放出子代噬菌体
B. 32P标记的一组感染实验,每个子代噬菌体都有放射性
C. 35S 标记的一组感染实验,保温时间过长可致上清液的放射性增强
D. 若用未标记的噬菌体侵染35S标记的大肠杆菌,则放射性主要分布在沉淀物中
7. 下图为某种动物细胞(2N =6)的有丝分裂后期图,图中部分染色体出现异常,数字代表染色体,不考虑基因突变。
下列相关叙述正确的是()
A. 该细胞中染色单体数为0。