2009年广西崇左中考数学试题及答案(word版)
2009年中考数学试题分类汇编之03 整式试题及答案
2009年中考试题专题之3-整式试题及答案一、选择题1.(2009年台湾)已知(19x -31)(13x -17)-(13x -17)(11x -23)可因式分解成(ax +b )(8x +c ),其中a 、b 、c 均为整数,则a +b +c =?A .-12B .-32C .38D .72 。
【关键词】分解因式 【答案】A2.(2009年台湾)将一多项式[(17x 2-3x +4)-(ax 2+bx +c )],除以(5x +6)后,得商式为(2x +1),余式为0。
求a -b -c =?A .3B .23C .25D .29 【关键词】整式除法运算 【答案】D3.(2009年重庆市江津区) 下列计算错误的是 ( ) A .2m + 3n=5mn B .426a a a =÷ C .632)(x x = D .32a a a =⋅ 【关键词】幂的运算 【答案】A4.(2009年重庆市江津区)把多项式a ax ax 22--分解因式,下列结果正确的是 ( ) A.)1)(2(+-x x a B. )1)(2(-+x x a C.2)1(-x a D. )1)(2(+-ax ax 【关键词】分解因式 【答案】A5.(2009年北京市)把3222x x y xy -+分解因式,结果正确的是 A.()()x x y x y +-B.()222x x xy y -+ C ()2x x y + D ()2x x y -【关键词】分解因式 【答案】D6. (2009年仙桃)下列计算正确的是( ). A 、235a a a += B 、623a a a ÷= C 、()326a a = D 、236a a a ⨯=【关键词】整式运算性质. 【答案】C7. (2009年四川省内江市) 在边长为a 的正方形中挖去一个边长为b 的小正方形(a >b )(如图甲),把余下的部分拼成一个矩形(如图乙),根据两个图形中阴影部分的面积相等,可以验证( )A .2222)(b ab a b a ++=+B .2222)(b ab a b a +-=-C .))((22b a b a b a -+=-D .222))(2(b ab a b a b a -+=-+【关键词】用不同形式的代数式来表示同一部分的面积。
广西崇左市中考数学试题(word版,含解析)
7.D【解析】
选项 A
B C D
逐项分析
正误
对角线互相垂直的平行四边形是菱形, √
对角线互相等的平行四边形是矩形,
对角线即垂直又相等的平行四边形是
正方形
对角线互相垂直的矩形是正方形
√
对角线互相相等的矩形是正方形
√
对角线即垂直又相等的四边形不一定 ×
3
是平行四边形,故不是正方形
点评:从对角线的角度来判断特殊平行四边形,首先要保证是平行四边形,即要保证对角线 互相平分,在此基础上再添加对角线相等或垂直.
数不变,指数相加,即 am an amn (m、n 为整数);②同底数幂的除法法则:同底数幂
相除,底数不变,指数相减,即 am an amn (a≠0,m、n 为整数,m>n);③幂的乘方
法则:幂的乘方,底数不变,指数相乘,即 (a m )n amn (m、n 为整数);④积的乘方法
则:把积的每一个因式分 别乘方,再把所有的幂相乘。即 (ab)n anbn (n 为整数).
1
17.如 30°只要小于 40 度即可.【解析】∠OBC= ∠AOC=40°,∠OBC>∠APC,故∠APC
2
<40°. 备考指导:(1)在同圆或等圆中圆周角的度数等于同弧或等弧所对的圆心角的一半.(2)三角形 的外角大于不相邻的一个内角.
18.(3 分)(2015•崇左)4 个数 a,b,c,d 排列成 ,我们称之为二阶行列式.规定它
8.(3 分)(2015•崇左)甲、乙、丙、丁四位同学在三次数学测验中,他们成绩的平均分是
=85, =85, =85, =85,方差是 S 甲 2=3.8,S 乙 2=2.3,S 丙 2=6.2,S 丁 2=5.2,则成
最新崇左市初中升学考试数学试卷
崇左市初中升学考试数学试卷2009年崇左市初中毕业升学考试数 学(全卷满分:120分;考试时间:120分钟)一、填空题:本大题共10小题;每小题2分,共20分.请将答案填写在题中的横线上.1.5-的绝对值是 .2.已知75A ∠=°,则A ∠的余角的度数是 . 3.在函数y =x 的取值范围是 .4.分解因式:2242x x -+= .5.写出一个图像位于第一、二、三象限内的一次函数表达式: . 6.一元二次方程230x mx ++=的一个根为1-,则另一个根为 .7.已知圆锥侧面积为28πcm ,侧面展开图圆心角为45°,则该圆锥的母线长为 cm .8.如图,点O 是O ⊙的圆心,点A B C 、、在O ⊙上,AO BC ∥,38AOB ∠=°,则OAC ∠的度数是 .9.当x ≤0时,化简1x -的结果是 .10.如图,正方形ABCD 中,E 是BC 边上一点,以E 为圆心、EC 为半径的半圆与以A 为圆心,AB 为半径的圆弧外切,则sin EAB ∠的值为 .二、选择题:本大题共8小题;每小题3分,共24分.在每小题给出的四个选项中,只有一项是正确的,请将正确答案前的字母填入题后的括号内,每小题选对得3分,选错、不选或多选均得0分.11.如图,直线c 截二平行直线a b 、,则下列式子中一定成立的是( )A .12∠=∠B .13∠=∠C .14∠=∠D .15∠=∠ 12.下列运算正确的是( )A .224236x x x =·B .22231x x -=-C .2222233x x x ÷= D .224235x x x += 13.一个等腰三角形的两边长分别为2和5,则它的周长为( )A .7B .9C .12D .9或12OC B A(第8题) D C E B A (第10题) 1 2 3 4 5 aPbP cP(第11题)14.不等式组221x x -⎧⎨-<⎩≤的整数解共有( )A .3个B .4个C .5个D .6个15.如图,下列选项中不是正六棱柱三视图的是( )A .B .C .D .A .9和10B .9.5和10C .10和9D .10和9.517.如图,把矩形ABCD 沿EF 对折后使两部分重合,若150∠=°,则AEF ∠=( ) A .110° B .115° C .120° D .130° 18.已知点A 的坐标为()a b ,,O 为坐标原点,连结OA ,将线段OA 绕点O 按逆时针方向旋转90°得1OA ,则点1A 的坐标为( )A .()a b -,B .()a b -,C .()b a -,D .()b a -,三、解答题:本大题共7小题,共76分. 19.(本小题满分6分)计算:0200912sin 603tan 30(1)3⎛⎫-++- ⎪⎝⎭°°.20.(本小题满分8分)已知220x -=,求代数式222(1)11x x x x -+-+的值.1AED C BF (第17题)21.(本小题满分10分)如图,ABC △中,D E 、分别是边BC AB 、的中点,AD CE 、相交于G .求证:13GE GD CE AD ==.22.(本小题满分10分)一只口袋中放着若干只红球和白球,这两种球除了颜色以外没有任何其他区别,袋中的球已经搅匀,蒙上眼睛从口袋中取出一只球,取出红球的概率是14.(1)取出白球的概率是多少?(2)如果袋中的白球有18只,那么袋中的红球有多少只?23.(本小题满分12分)五一期间某校组织七、八年级的同学到某景点郊游,该景点的门票全票票价为15元/人,若为50~99人可以八折购票,100人以上则可六折购票.已知参加郊游的七年级同学少于50人,八年级同学多于50人而少于100人.若七、八年级分别购票,两个年级共计应付门票费1575元,若合在一起购买折扣票,总计应付门票费1080元.问:(1)参加郊游的七、八年级同学的总人数是否超过100人? (2)参加郊游的七、八年级同学各为多少人?B CG E A (第21题)24.(本小题满分14分)如图,在等腰梯形ABCD 中,已知AD BC ∥,24AB DC AD BC ===,,,延长BC 到E ,使CE AD =.(1)证明:BAD DCE △≌△;(2)如果AC BD ⊥,求等腰梯形ABCD 的高DF 的值.25.(本小题满分16分)在平面直角坐标系中,现将一块等腰直角三角板ABC 放在第二象限,斜靠在两坐标轴上,且点(02)A ,,点(10)C -,,如图所示:抛物线22y ax ax =+-经过点B .(1)求点B 的坐标;(2)求抛物线的解析式;(3)在抛物线上是否还存在点P (点B 除外),使ACP △仍然是以AC 为直角边的等腰直角三角形?若存在,求所有点P 的坐标;若不存在,请说明理由.D A B EC F (第24题)(第25题)2009年崇左市初中毕业升学考试数 学 答 案一、1.5 2.15° 3.3x -≥ 4.22(1)x - 5.1y x =+等6.3- 7.8 8.19° 9.1 10.35二、11.B 12.A 13.C 14.C 15A 16.D 17.B 18.C三、19.原式=231123⨯-⨯+- ····················································· 4分=0. ··········································································· 6分20.原式=22(1)(1)(1)1x x x x x -+-++ ······························································ 2分=2111x x x x -+++······································································ 4分 =211x x x +-+ ········································································ 5分 220x -=,22x ∴= ··········································································· 6分 ∴原式211x x +-=+ ·································································· 7分∴原式=1 ············································································ 8分21.证明:连结ED , ······································· 1分D E 、分别是边BC AB 、的中点,12DE DE AC AC ∴=∥,, ······································· 3分ACG DEG ∴△∽△, ········································· 5分12GE GD DE GC AG AC ∴===, ····································· 7分 13GE GD CE AD ∴==. ··········································································· 10分 22.(1)()()P 1P =-取出白球取出红球 ··························································· 3分=13144-= ······················································································· 4分BCGE A(2)设袋中的红球有x 只,则有 ························································ 5分 1184x x =+ (或183184x =+) ····························································· 8分 解得6x =所以,袋中的红球有6只. ······························································· 10分 23.(1)全票为15元,则八折票价为12分,六折票价为9元. ·············· 2分 1001515001575⨯=< ······································································ 4分∴参加郊游的七、八年级同学的总人数必定超过100人. ························ 5分 (2)设七、八年级参加郊游的同学分别有x 人、y 人 ····························· 6分由(1)及已知,5050100100x y x y <<<+>,,. ·································· 7分 依题意可得: 151215759()1080x y x y +=⎧⎨+=⎩ ············································································ 10分 解得4575x y =⎧⎨=⎩ ························································································ 11分 答:参加郊游的七、八年级同学分别为45人和75人. ·························· 12分24.(1)证明:AD BC CDA DCE ∴∠=∠∥,. ··································· 1分 又四边形ABCD 是等腰梯形,BAD CDA ∴∠=∠, ································ 2分BAD DCE ∴∠=∠. ········································································· 3分AB DC AD CE ==,, BAD DCE ∴△≌△. ········································································ 5分(2)AD CE AD BC =∴,∥,四边形ACED 是平行四边形, ···················· 7分 AC DE ∴∥. ················································································· 8分 AC BD DE BD ⊥∴⊥,. ·································································· 9分 由(1)可知,BAD DCE △≌△,DE BD ∴=. ···································· 10分 所以,BDE △是等腰直角三角形,即45E ∠=°,DF FE FC CE ∴==+. ··································································· 12分 四边形ABCD 是等腰梯形,而24AD BC ==,, 1FC ∴=. ···················································································· 13分2CE AD == 3DF ∴=. ···················································································· 14分 25.(1)过点B 作BD x ⊥轴,垂足为D , 9090BCD ACO ACO CAO ∠+∠=∠+∠=°,° BCD CAO ∴∠=∠; ··································· 1分又90BDC COA CB AC ∠=∠==°;, BCD CAO ∴△≌△, ··································· 2分12BD OC CD OA ∴====,························· 3分∴点B 的坐标为(31)-,; ······························ 4分(2)抛物线22y ax ax =+-经过点(31)B -,,则得到1932a a =--, ············ 5分 解得12a =,所以抛物线的解析式为211222y x x =+-; ···························· 7分(3)假设存在点P ,使得ACP △仍然是以AC 为直角边的等腰直角三角形:①若以点C 为直角顶点;则延长BC 至点1P ,使得1PC BC =,得到等腰直角三角形1ACP △, ············ 8分过点1P 作1PMx ⊥轴, 11190CP BC MCP BCD PMC BDC =∠=∠∠=∠=,,°; 1MPC DBC ∴△≌△ ·········································································· 10分 121CM CD PM BD ∴====,,可求得点1P (1,-1); ····························· 11分 ②若以点A 为直角顶点;则过点A 作2AP CA ⊥,且使得2AP AC =,得到等腰直角三角形2ACP △, ··· 12分过点2P 作2P N y ⊥轴,同理可证2AP N CAO △≌△; ······························· 13分221NP OA AN OC ∴====,,可求得点2(21)P ,; ·································· 14分 经检验,点1(11)P -,与点2(21)P ,都在抛物线211222y x x =+-上. ··············· 16分。
2009年中考数学试题汇编之三角形与全等三角形试题及答案[1]
2009年中考试题专题之16-三角形与全等三角形试题及答案一、选择题 1.(2009年江苏省)如图,给出下列四组条件: ①AB DE BC EF AC DF ===,,; ②AB DE B E BC EF =∠=∠=,,; ③B E BC EF C F ∠=∠=∠=∠,,; ④AB DE AC DF B E ==∠=∠,,.其中,能使ABC DEF △≌△的条件共有( ) A .1组 B .2组 C .3组 D .4组2.(2009年浙江省绍兴市)如图,D E ,分别为ABC △的AC ,BC 边的中点,将此三角形沿DE 折叠,使点C 落在AB 边上的点P 处.若48CDE ∠=°,则APD ∠等于( ) A .42° B .48° C .52° D .58°3. (2009年义乌)如图,在ABC 中,90C ∠=。
,EF//AB,150∠=。
,则B ∠的度数为A .50。
B. 60。
C.30。
D. 40。
【关键词】三角形内角度数【答案】D4.(2009年济宁市)如图,△ABC 中,∠A =70°,∠B =60°,点D 在BC 的延长线上,则∠ACD 等于A. 100°B. 120°C. 130°D. 150°A BD5、(2009年衡阳市)如图2所示,A 、B 、C 分别表示三个村庄,AB=1000米,BC=600米,AC=800米,在社会主义新农村建设中,为了丰富群众生活,拟建一个 文化活动中心,要求这三个村庄到活动中心的距离相等,则活动中心P 的位置应在( ) A .AB 中点 B .BC 中点 C .AC 中点 D .∠C 的平分线与AB 的交点6、(2009年海南省中考卷第5题)已知图2中的两个三角形全等,则∠α度数是( )A.72°B.60°C.58°D.50° 7、(2009 黑龙江大兴安岭)如图,为估计池塘岸边A 、B 两点的距离,小方在池塘的一侧选取一点O ,测得15=OA 米,10=OB 米,A 、B 间的距离不可能是 ( ) A .5米 B .10米 C . 15米 D .20米8、(2009年崇左)一个等腰三角形的两边长分别为2和5,则它的周长为( ) A .7 B .9 C .12 D .9或12 9、(2009年湖北十堰市)下列命题中,错误的是( ). A .三角形两边之和大于第三边 B .三角形的外角和等于360° C .三角形的一条中线能将三角形面积分成相等的两部分 D .等边三角形既是轴对称图形,又是中心对称图形10、(09湖南怀化)如图,在Rt ABC △中,90=∠B ,ED 是AC 的垂直平分线,交AC 于点D ,交BC 于点E .已知10=∠BAE ,则C ∠的度数为( )A .30 B .40 C .50 D .6011、(2009年清远)如图,AB CD ∥,EF AB ⊥于E EF ,交CD 于F ,已知160∠=°,则2∠=( )A .20°B .60°C .30°D .45°A DB12、(2009年广西钦州)如图,在等腰梯形ABCD 中,AB =DC ,AC 、BD 交于点O ,则图中全等三角形共有( ) A .2对 B .3对C .4对D .5对【形ADO13、(2009年甘肃定西)如图4,四边形ABCD 中,AB =BC ,∠ABC =∠CDA =90°,BE ⊥AD于点E ,且四边形ABCD 的面积为8,则BE =( )A .2B .3C.D.14、(2009年广西钦州)如图,AC =AD ,BC =BD ,则有( ) A .AB 垂直平分CD B .CD 垂直平分AB C .AB 与CD 互相垂直平分D .CD 平分∠ACBABCD15、(2009肇庆)如图,Rt ABC △中, 90ACB ∠=°,DE 过点C ,且DE AB ∥,若 55ACD ∠=°,则∠B 的度数是( ) A .35° B .45° C .55° D .65°CDB AEF12A B E21CDBA16、(2009年邵阳市)如图,将Rt △ABC(其中∠B =340,∠C =900)绕A 点按顺时针方向旋转到△AB 1 C 1的位置,使得点C 、A 、B 1 在同一条直线上,那么旋转角最小等于( ) A.560B.680C.1240D.180017、(2009年湘西自治州)一个角是80°,它的余角是( )A .10°B .100°C .80°D .120°18、(2009河池)如图,在Rt △ABC 中,90∠=A ,AB =AC= E 为AC 的中点,点F 在底边BC 上,且⊥FE BE ,则△CEF 的面积是( )A . 16B . 18C .D .19、(2009柳州)如图所示,图中三角形的个数共有( ) A .1个 B .2个 C .3 个 D .4个20、(2009年牡丹江)如图, ABC △中,CD AB ⊥于D ,一定能确定ABC △为直角三角形的条件的个数是( ) ①1A ∠=∠,②CD DBAD CD=,③290B ∠+∠=°,④345BC AC AB =∶∶∶∶,⑤ACBD AC CD =·· A .1 B .2 C .3 D .4 【21、(2009桂林百色)如图所示,在方格纸上建立的平面直角坐标系中, 将△ABO 绕点O 按顺时针方向旋转90°, 得A B O ''△ ,则点A '的坐标为( ).A .(3,1)B .(3,2)C .(2,3)D .(1,3)22、(2009年长沙)已知三角形的两边长分别为3cm 和8cm ,则此三角形的第三边的长可能是( )A .4cmB .5cmC .6cmD .13cm 23、(2009年湖南长沙)已知三角形的两边长分别为3cm 和8cm ,则此三角形的第三边的长1C ACFAEC D BA可能是( ) A .4cm B .5cm C .6cm D .13cm24、(2009陕西省太原市)如图,ACB A C B '''△≌△,BCB ∠'=30°,则ACA '∠的度数为( ) A .20° B .30° C .35°D .40°25、 (2009陕西省太原市)如果三角形的两边分别为3和5,那么连接这个三角形三边中点,所得的三角形的周长可能是( )A .4B .4.5C .5D .5.526、(2009年牡丹江)尺规作图作AOB ∠的平分线方法如下:以O 为圆心,任意长为半径画弧交OA 、OB 于C 、D ,再分别以点C 、D 为圆心,以大于12CD 长为半径画弧,两弧交于点P ,作射线OP ,由作法得OCP ODP △≌△的根据是( ) A .SAS B .ASA C .AAS D .SSS27、(2009年新疆)如图,将三角尺的直角顶点放在直尺的一边上,130250∠=∠=°,°,则3∠的度数等于( ) A .50° B .30° C .20° D .15°28、(2009年牡丹江市)尺规作图作AOB ∠的平分线方法如下:以O 为圆心,任意长为半径画弧交OA 、OB 于C 、D ,再分别以点C 、D 为圆心,以大于12CD 长为半径画弧,两弧交于点P ,作射线OP ,由作法得OCP ODP △≌△的根据是( ) A .SAS B .ASA C .AAS D .SSS123C AB B 'A '【29、(2009年包头)已知在Rt ABC △中,390sin 5C A ∠==°,,则tan B 的值为( ) A .43B .45C .54D .34【30、(2009年齐齐哈尔市)如图,为估计池塘岸边A B 、的距离,小方在池塘的一侧选取一点O ,测得15OA =米,OB =10米,A B 、间的距离不可能是( ) A .20米 B .15米 C .10米 D .5米31、(2009年台湾)图(三)、图(四)、图(五)分别表示甲、乙、丙三人由A 地到B 地的路线图。
广西崇左初中毕业考试数学试题-解析版
广西崇左市中考数学试卷一、填空题(本大题共10小题,每小题2分,满分20分.)1、(2004•湟中县)分解因式:x2y﹣4xy+4y=y(x﹣2)2.考点:提公因式法与公式法的综合运用。
分析:先提取公因式y,再对余下的多项式利用完全平方公式继续分解.解答:解:x 2y ﹣4xy+4y ,=y(x2﹣4x+4),=y(x﹣2)2.点评:本题考查了提公因式法,公式法分解因式,难点在于提取公因式后要进行二次分解因式,分解因式要彻底.2、(2011•广西)如图,O是直线AB上一点,∠COB=30°,则∠1=150°考点:对顶角、邻补角。
专题:计算题。
分析:根据邻补角互补进行计算即可.解答:解:∵∠COB=30°,∴∠1=180°﹣30°=150°.故答案为:150.点评:本题考查了邻补角的定义,利用两个补角的和等于180°求解.3、(2011•台州)若二次根式有意义,则x的取值范围是x≥1.考点:二次根式有意义的条件。
分析:根据二次根式的性质可知,被开方数大于等于0,列出不等式即可求出x的取值范围.解答:解:根据二次根式有意义的条件,x﹣1≥0,x≥1.故答案为x≥1.点评:此题考查了二次根式有意义的条件,只要保证被开方数为非负数即可.4、(2011•广西)方程组的解是x=1,y=2.考点:解二元一次方程组。
专题:计算题。
分析:用加减法解方程组即可.解答:解:,①+②得:8x=8,x=1,把x=1代入①得:y=2,∴,故答案为:x=1,y=2.点评:此题考查的知识点是解二元一次方程组,关键是运用加减消元法求解.5、(2011•广西)在修建崇钦高速公路时,有时需要将弯曲的道路改直,依据是两点之间线段最短.考点:线段的性质:两点之间线段最短。
分析:根据线段的性质:两点之间线段最短解答.解答:解:在修建崇钦高速公路时,有时需要将弯曲的道路改直,依据是:两点之间线段最短.故答案为:两点之间线段最短.点评:本题考查了两点之间线段最短的性质,是基础题,比较简单.6、(2011•广西)下面图形:四边形,三角形,梯形,平行四边形,菱形,矩形,正方形,圆,从中任取一个图形既是轴对称图形又是中心对称图形的概率是..考点:概率公式;轴对称图形;中心对称图形。
2009年广西南宁市中考数学试卷(A4)
2009年广西南宁市中考数学试卷一、选择题(共12小题,每小题3分,满分36分)1.(3分)(2010•郴州)的相反数是()D.3.(3分)(2009•南宁)今年6月,南宁市举行了第五届泛珠三角区域经贸合作洽谈会.据估算,本届大会合同投.C D.5.(3分)(2009•南宁)不等式组的解集在数轴上表示为().C D.6.(3分)(2010•内江)在函数中,自变量x的取值范围是()线(虚线)剪下,再打开,得到的菱形的面积为()29.(3分)(2010•海南)在反比例函数y=的图象的每一条曲线上,y都随x的增大而增大,则k的值可以是()10.(3分)(2009•南宁)如图,AB是⊙O的直径,弦CD⊥AB于点E,∠CDB=30°,⊙O的半径为cm,则弦CD的长为().cm cm11.(3分)(2009•南宁)已知二次函数y=ax2+bx+c(a≠0)的图象如图所示,有下列四个结论:①b<0;②c>0;③b2﹣4ac>0;④a﹣b+c<0,其中正确的个数有()12.(3分)(2009•南宁)从2,3,4,5这四个数中,任取两个数p和q(p≠q),构成函数y=px﹣2和y=x+q,并二、填空题(共6小题,每小题2分,满分12分)13.(2分)(2009•南宁)如图,直线a、b被c所截,且a∥b,∠1=120°,则∠2=_________度.14.(2分)(2009•南宁)计算:(a2b)2÷a=_________.15.(2分)(2009•南宁)三角尺在灯泡O的照射下在墙上形成影子(如图所示).现测得OA=20cm,OA′=50cm,这个三角尺的周长与它在墙上形成的影子的周长的比是_________.16.(2分)(2009•南宁)有五张分别印有圆、等腰三角形、矩形、菱形、正方形图案的卡片(卡片中除图案不同外,其余均相同),现将有图案的一面朝下任意摆放,从中任意抽取一张,抽到有中心对称图案的卡片的概率是_________.17.(2分)(2009•南宁)如图,一艘海轮位于灯塔P的东北方向,距离灯塔40海里的A处,它沿正南方向航行一段时间后,到达位于灯塔P的南偏东30°方向上的B处,则海轮行驶的路程AB为_________海里(结果保留根号).20行,第21列的数字_________.三、解答题(共8小题,满分72分)19.(6分)(2009•南宁)计算:(﹣1)2009+|﹣|﹣()﹣1﹣sin60°.20.(6分)(2009•南宁)先化简,再求值:(1+)÷﹣(x﹣2),其中x=.21.(10分)(2009•南宁)为迎接国庆60周年,某校举行以“祖国成长我成长”为主题的图片制作比赛,赛后整理参(1)表中m和n所表示的数分别为:m=_________,n=_________;(2)请在图中,补全频数分布直方图;(3)比赛成绩的中位数落在哪个分数段;(4)如果比赛成绩80分以上(含80分)可以获得奖励,那么获奖率是多少?22.(10分)(2009•南宁)已知△ABC在平面直角坐标系中的位置如图所示.(1)分别写出图中点A和点C的坐标;(2)画出△ABC绕点C按顺时针方向旋转90°后的△A′B′C′;(3)求点A旋转到点A′所经过的路线长(结果保留π).23.(10分)(2009•南宁)如图,PA、PB是半径为1的⊙O的两条切线,点A、B分别为切点,∠APB=60°,OP 与弦AB交于点C,与⊙O交于点D.(1)在不添加任何辅助线的情况下,写出图中所有的全等三角形;(2)求阴影部分的面积(结果保留π).24.(10分)(2009•南宁)南宁市狮山公园计划在健身区铺设广场砖.现有甲、乙两个工程队参加竞标,甲工程队铺设广场砖的造价y甲(元)与铺设面积x(m2)的函数关系如图所示;乙工程队铺设广场砖的造价y乙(元)与铺设面积x(m2)满足函数关系式:y乙=kx.(1)根据图写出甲工程队铺设广场砖的造价y甲(元)与铺设面积x(m2)的函数关系式;(2)如果狮山公园铺设广场砖的面积为1600m2,那么公园应选择哪个工程队施工更合算?25.(10分)(2009•南宁)如图1,在边长为5的正方形ABCD中,点E、F分别是BC、DC边上的点,且AE⊥EF,BE=2.(1)求EC:CF的值;(2)延长EF交正方形外角平分线CP于点P(如图2),试判断AE与EP的大小关系,并说明理由;(3)在图2的AB边上是否存在一点M,使得四边形DMEP是平行四边形?若存在,请给予证明;若不存在,请说明理由.26.(10分)(2009•南宁)如图,要设计一个等腰梯形的花坛,花坛上底长120米,下底长180米,上下底相距80米,在两腰中点连线(虚线)处有一条横向甬道,上下底之间有两条纵向甬道,各甬道的宽度相等.设甬道的宽为x米.(1)用含x的式子表示横向甬道的面积;(2)根据设计的要求,甬道的宽不能超过6米.如果修建甬道的总费用(万元)与甬道的宽度成正比例关系,比例系数是5.7,花坛其余部分的绿化费用为每平方米0.02万元,那么当甬道的宽度为多少米时,所建花坛的总费用为239万元?2009年广西南宁市中考数学试卷参考答案与试题解析一、选择题(共12小题,每小题3分,满分36分)1.(3分)(2010•郴州)的相反数是()D.的相反数为﹣.2.(3分)(2009•南宁)如图是一个五边形木架,它的内角和是()3.(3分)(2009•南宁)今年6月,南宁市举行了第五届泛珠三角区域经贸合作洽谈会.据估算,本届大会合同投4.(3分)(2010•日照)如图是一个三视图,则此三视图所对应的直观图是().C D.5.(3分)(2009•南宁)不等式组的解集在数轴上表示为().C D.得:6.(3分)(2010•内江)在函数中,自变量x的取值范围是()解:根据题意得:7.(3分)(2009•南宁)如图,将一个长为10cm,宽为8cm的矩形纸片对折两次后,沿所得矩形两邻边中点的连线(虚线)剪下,再打开,得到的菱形的面积为()=29.(3分)(2010•海南)在反比例函数y=的图象的每一条曲线上,y都随x的增大而增大,则k的值可以是()对于函数的图象上的每一条曲线上,学生对解析式10.(3分)(2009•南宁)如图,AB是⊙O的直径,弦CD⊥AB于点E,∠CDB=30°,⊙O的半径为cm,则弦CD的长为().cm cmOC=CE=cm11.(3分)(2009•南宁)已知二次函数y=ax2+bx+c(a≠0)的图象如图所示,有下列四个结论:①b<0;②c>0;③b2﹣4ac>0;④a﹣b+c<0,其中正确的个数有()12.(3分)(2009•南宁)从2,3,4,5这四个数中,任取两个数p和q(p≠q),构成函数y=px﹣2和y=x+q,并x=右侧,即二、填空题(共6小题,每小题2分,满分12分)13.(2分)(2009•南宁)如图,直线a、b被c所截,且a∥b,∠1=120°,则∠2=60度.14.(2分)(2009•南宁)计算:(a2b)2÷a=a3b2.15.(2分)(2009•南宁)三角尺在灯泡O的照射下在墙上形成影子(如图所示).现测得OA=20cm,OA′=50cm,这个三角尺的周长与它在墙上形成的影子的周长的比是2:5.,.16.(2分)(2009•南宁)有五张分别印有圆、等腰三角形、矩形、菱形、正方形图案的卡片(卡片中除图案不同外,其余均相同),现将有图案的一面朝下任意摆放,从中任意抽取一张,抽到有中心对称图案的卡片的概率是.所以概率为=17.(2分)(2009•南宁)如图,一艘海轮位于灯塔P的东北方向,距离灯塔40海里的A处,它沿正南方向航行一段时间后,到达位于灯塔P的南偏东30°方向上的B处,则海轮行驶的路程AB为()海里(结果保留根号).AP=×AB=AC+BC=40+列的数字420.三、解答题(共8小题,满分72分)19.(6分)(2009•南宁)计算:(﹣1)2009+|﹣|﹣()﹣1﹣sin60°.﹣,|20.(6分)(2009•南宁)先化简,再求值:(1+)÷﹣(x﹣2),其中x=.时,原式21.(10分)(2009•南宁)为迎接国庆60周年,某校举行以“祖国成长我成长”为主题的图片制作比赛,赛后整理参(1)表中m和n所表示的数分别为:m=,n=;(2)请在图中,补全频数分布直方图;(3)比赛成绩的中位数落在哪个分数段;(4)如果比赛成绩80分以上(含80分)可以获得奖励,那么获奖率是多少?==故获奖率为22.(10分)(2009•南宁)已知△ABC在平面直角坐标系中的位置如图所示.(1)分别写出图中点A和点C的坐标;(2)画出△ABC绕点C按顺时针方向旋转90°后的△A′B′C′;(3)求点A旋转到点A′所经过的路线长(结果保留π).23.(10分)(2009•南宁)如图,PA、PB是半径为1的⊙O的两条切线,点A、B分别为切点,∠APB=60°,OP 与弦AB交于点C,与⊙O交于点D.(1)在不添加任何辅助线的情况下,写出图中所有的全等三角形;(2)求阴影部分的面积(结果保留π).APO=×24.(10分)(2009•南宁)南宁市狮山公园计划在健身区铺设广场砖.现有甲、乙两个工程队参加竞标,甲工程队铺设广场砖的造价y甲(元)与铺设面积x(m2)的函数关系如图所示;乙工程队铺设广场砖的造价y乙(元)与铺设面积x(m2)满足函数关系式:y乙=kx.(1)根据图写出甲工程队铺设广场砖的造价y甲(元)与铺设面积x(m2)的函数关系式;(2)如果狮山公园铺设广场砖的面积为1600m2,那么公园应选择哪个工程队施工更合算?=5625.(10分)(2009•南宁)如图1,在边长为5的正方形ABCD中,点E、F分别是BC、DC边上的点,且AE⊥EF,BE=2.(1)求EC:CF的值;(2)延长EF交正方形外角平分线CP于点P(如图2),试判断AE与EP的大小关系,并说明理由;(3)在图2的AB边上是否存在一点M,使得四边形DMEP是平行四边形?若存在,请给予证明;若不存在,请说明理由.中∴△26.(10分)(2009•南宁)如图,要设计一个等腰梯形的花坛,花坛上底长120米,下底长180米,上下底相距80米,在两腰中点连线(虚线)处有一条横向甬道,上下底之间有两条纵向甬道,各甬道的宽度相等.设甬道的宽为x米.(1)用含x的式子表示横向甬道的面积;(2)根据设计的要求,甬道的宽不能超过6米.如果修建甬道的总费用(万元)与甬道的宽度成正比例关系,比例系数是5.7,花坛其余部分的绿化费用为每平方米0.02万元,那么当甬道的宽度为多少米时,所建花坛的总费用为239万元?)根据题意得出横向甬道的面积为(。
2009年广西桂林市中考数学试卷及答案-(word整理版)
2009年广西桂林市中考数学试卷-(word 整理版)一、选择题(共12小题,每小题3分,共36分 1. 的相反数是( ).A .B .8C .D .2.下面的几个有理数中,最大的数是( ).A .2B .C .-3D .3.如图,在所标识的角中,同位角是( ).A .和B .和C .和D .和 4.右图是一正四棱锥,它的俯视图是( ).A .B .C .D . 5.下列运算正确的是( ).A .B .C .·=D . 6.二次函数的最小值是( ).A .2B .1C .-3D . 7.右图是一张卡通图,图中两圆的位置关系是( ). A .相交 B .外离 C .内切 D .内含8.已知是二元一次方程组的解,则的值为( ).A .1B .-1C . 2D .39.有20张背面完全一样的卡片,其中8张正面印有桂林山水,7张正面印有百色风光,5张正面印有北海海景;把这些卡片的背面朝上搅匀,从中随机抽出一张卡片,抽中正面是桂林山水卡片的概率是( ).A .B .C .D .10.如图,□ABCD 中,AC 、BD 为对角线,BC =6,BC 边上的高为4,则阴影部分的面积是( ) A .3 B .6 C .12 D .2411.如图所示,在方格纸上建立的平面直角坐标系中,将△ABO 绕点O 按顺时针方向旋转90°,得,则点的坐标为( ). A .(3,1) B .(3,2)C .(2,3) D .(1,3)12.如图,正方形ABCD 的边长为2,将长为2的线段QR 的两端放在正方形的相邻的两边上同时滑动.如 果Q 点从A 点出发,沿图中所示方向按A→B→C→D→A 滑动到A 止,同时点R 从B 点出发,沿图中所 示方向按B→C→D→A→B 滑动到B 止,在这个过程中,线段QR 的中点M 所经过的路线围成的图形的 面积为( ).A .2B .C .D . 二.填空题(共6道小题,每小题3分,共18分) 13.因式分解: .14.据统计,去年我国粮食产量达10570亿斤,用科学记数法表示为 亿斤.15.如图,在一次数学课外活动中,测得电线杆底部B 与钢缆固定点C 的距离为4米,钢缆与地面的夹角为60º,则这条钢缆在电线杆上的固定点A 到地面的距离AB 是 米.16.在函数中,自变量的取值范围是 .17.如图,是一个正比例函数的图像,把该图像向左平移一个单位长度,得到的函数图像的解析式为 .18.如图,在△ABC 中,∠A =.∠ABC 与∠ACD 的平分线交于点A 1,得∠A 1;∠A 1BC 与∠A 1CD 的平分线相交于点A 2,得∠A 2; ……;∠A 2008BC 与∠A 2008CD 的平分线相交于点A 2009,得∠A 2009 .则∠A 2009= .三、解答题(本大题共8题,共66分)19.(6分)计算:º-8-8-1818-1315-1∠2∠1∠3∠1∠4∠2∠3∠22a b ab +=222()ab a b -=2a 2a 22a 422a a ÷=2(1)2y x =++2321x y =⎧⎨=⎩71ax by ax by +=⎧⎨-=⎩a b -147202558A B O ''△A '4π-ππ1-23x x +=y =x α101()(20094sin 302---+2-1 2 3 4 (第3题图) (第4题图)(第7题图) B图10xy1 2 430 ---12 3AB第11题第12题图第15题图x第17题图BACD第18题图 A 1A 220.(6分)先化简,再求值:,其中.21.(8分)如图:在等腰梯形ABCD 中,AD ∥BC ,对角线AC 、BD 相交于O . (1)图中共有 对全等三角形;(2)写出你认为全等的一对三角形,并证明.22. (8分)2008年11月28日,为扩大内需,国务院决定在全国实施“家电下乡”政策.第一批列入家电下乡的产品为彩电、冰箱、洗衣机和手机四种产品.某县一家家电商场,今年一季度对以上四种产品的销售情况进行了统计,绘制了如下的统计图,请你根据图中信息解答下列问题:(1)该商场一季度彩电销售的数量是 台.(2) 请补全条形统计图和扇形统计图.2211()22x yx y x x y x+--++3x y == A D O CB 第21题图数量(台23.(8分)在保护地球爱护家园活动中,校团委把一批树苗分给初三(1)班同学去栽种.如果每人分2棵,还剩42棵;如果前面每人分3棵,那么最后一人得到的树苗少于5棵(但至少分得一棵).(1)设初三(1)班有名同学,则这批树苗有多少棵?(用含的代数式表示).(2)初三(1)班至少有多少名同学?最多有多少名24.(8分)在我市某一城市美化工程招标时,有甲、乙两个工程队投标.经测算:甲队单独完成这项工程需要60天;若由甲队先做20天,剩下的工程由甲、乙合做24天可完成.(1)乙队单独完成这项工程需要多少天?(2)甲队施工一天,需付工程款3.5万元,乙队施工一天需付工程款2万元.若该工程计划在70天内完成,在不超过计划天数的前提下,是由甲队或乙队单独完成该工程省钱?还是由甲乙两队全程合作完成该工程省钱?x x25. (10分)如图,△ABC 内接于半圆,AB 是直径,过A 作直线MN ,若∠MAC=∠ABC . (1)求证:MN 是半圆的切线;(2)设D 是弧AC 的中点,连结BD 交AC 于G ,过D 作DE ⊥AB 于E ,交AC 于F . 求证:FD =FG .(3)若△DFG 的面积为4.5,且DG =3,GC =4,试求△BCG 的面积.26.(12分)如图,已知直线,它与轴、轴的交点分别为A 、B 两点. (1)求点A 、点B 的坐标;(2)设F 是轴上一动点,用尺规作图作出⊙P ,使⊙P 经过点B 且与轴相切于点F (不写作法和证明,保留作图痕迹);(3)设(2)中所作的⊙P 的圆心坐标为P (),求与的函数关系式;4)是否存在这样的⊙P ,既与轴相切又与直线相切于点B ,若存在,求出圆心P 的坐标;若不存在,请说明理由.3:34l y x =+x y x x x y ,y x x l第26题图MN A E D CG B 第25题图 F2009年广西桂林市中考数学试卷答案13. 14.1.057×104 15.16.≥ 17.或 18.19.解:原式=2-1+4×-2 4分 =1 ····························································································································· 6分 20.解:原式 ···················································· 2分 ··········································································································· 3分 ························································································································· 4分 ································································································································ 5分 把 ································································· 6分21.解:(1)3 …………………………………………………………………………………3分(写1对、2对均不给分)(2)△ABC ≌△DCB ······································································································ 4分 证明:∵四边形ABCD 是等腰梯形∴AB =DC ,∠ABC =∠DCB ············································································· 6分又BC =CB∴△ABC ≌△DCB ·························································································· 8分(注:选其它两对证明的,按以上相应步骤给分,全等三角形对应点不对应不扣分) 22.解(1)150 ················································································································· (2分) (2)10% ···················································································································· (2分) (3)每正确补全一个图形给2分,其中扇形统计图每补全一个扇形给1分.23.解(1)这批树苗有()棵 ·················································································· 1分 (2)根据题意,得 ·································································· 5分(每列对一个不等式给2分)解这个不等式组,得40<≤44 ···················································································· 7分答:初三(1)班至少有41名同学,最多有44名同学. ····················································· 8分 24.解:(1)设乙队单独完成需天 ······················································································· 1分根据题意,得························································· 3分 解这个方程,得=90 ··························································································· 4分 经检验,=90是原方程的解∴乙队单独完成需90天 ······················································································· 5分 (2)设甲、乙合作完成需天,则有 解得(天) ········································································································· 6分 甲单独完成需付工程款为60×3.5=210(万元)乙单独完成超过计划天数不符题意(若不写此行不扣分). 甲、乙合作完成需付工程款为36(3.5+2)=198(万元) ········································· 7分 答:在不超过计划天数的前提下,由甲、乙合作完成最省钱. ······························ 8分 25.证明(1):∵AB 是直径∴∠ACB =90º ,∴∠CAB +∠ABC =90º ······························································ 1分∵∠MAC =∠ABC∴∠MAC +∠CAB =90º,即MA ⊥AB∴M N 是半圆的切线. ····································· 2分(2)证法1:∵D 是弧AC 的中点, ∴∠DBC =∠2 ·············· 3分 ∵AB 是直径,∴∠CBG +∠CGB =90º ∵DE ⊥AB ,∴∠FDG +∠2=90º ······················· 4分 ∵∠DBC =∠2,∴∠FDG =∠CGB =∠FGD ∴FD =FG ······························································ 5分证法2:连结AD ,则∠1=∠2 ······························· 3分∵AB 是直径,∴∠ADB =90º ∴∠1+∠DGF =90º又∵DE ⊥AB ∴∠2+∠FDG =90º ·········································································· 4分 ∴∠FDG =∠FGD , ∴FD =FG ············································································· 5分(3)解法1:过点F 作FH ⊥DG 于H , ········································································ 6分又∵DF =FG ∴S △FGH =S △DFG =×4.5= ························································ 7分 ∵AB 是直径,FH ⊥DG ∴∠C =∠FHG =90º ····················································· 8分∵∠HGF =∠CGB ,∴△FGH ∽△BGC ∴···································································· 9分 ∴S △BCG = ························································································· 10分解法2:∵∠ADB =90º,DE ⊥AB ,∴∠3=∠2 ····························································· 6分∵∠1=∠2, ∴∠1=∠3 ∴AF =DF =FG ···································································································· 7分(3)x x +x 222y x =--2(1)y x =-+20092α12111()()22x yx y x y x x y x y x+=-+--⋅++1122x y x x=---()()x y =--y x =-3x y ==代入上式,得原式=3242x +2423(1)52423(1)1x x x x +--<⎧⎨+--⎩≥x x 11120()2416060x ⨯++⨯=x x y 11()16090y +=36y =121294221.59()()464FGH BGC S HG S CG ∆∆===9641649⨯=数量(台MN AE D CGB 2 FH 31∴S △ADG =2S △DFG =9 ······························································································ 8分 ∵∠ADG =∠BCG ,∠DGA =∠CGB ∴△ADG ∽△BCG ··························································································· 9分 ∴∴S △BCG =························································································ 10分 解法3:连结AD ,过点F 作FH ⊥DG 于H ,∵S △FDG =DG ×FH =×3FH =4.5 ∴FH =3 ················································································································· 6分∵H 是DG 的中点,FH ∥AD ∴AD =2FH =6 ········································································································ 7分∴S △ADG = ·································································· 8分(以下与解法2同)26.解(1)A (,0),B (0,3) ·················································· 2分(每对一个给1分) (2)满分3分.其中过F 作出垂线1分,作出BF 中垂线1分,找出圆心并画出⊙P 给1分. (注:画垂线PF 不用尺规作图的不扣分)(3)过点P 作PD ⊥轴于D ,则PD =,BD =,··············· 6分PB =PF =,∵△BDP 为直角三形, ∴∴ ································ 7分即 即 ∴与的函数关系为 ··················································································· 8分 (4)存在解法1:∵⊙P 与轴相切于点F ,且与直线相切于点B ∴ ······························································································································ 9分 ∵ ∴∵AF = , ∴ ······················································································ 10分 ∴······················································································································ 11分 把代入,得 ∴点P 的坐标为(1,)或(9,15)··········································································· 12分22416()()39BCG ADG S CG S DG ===△△169169⨯=12121163922AD DG ⋅=⨯⨯=4-y x 3y -y 222PB PD BD =+222BP PD BD =+2223y x y =+-222(3)y x y =+-y x 21362y x =+x l AB AF =22225AB OA OB =+=225AF =4x +22(4)5x +=19x x ==-或19x x ==-或21362y x =+5153y y ==或53-。
2009年中考数学试题分类汇编之02 无理数及二次根式
一、选择题1.(2009年绵阳市)已知n -12是正整数,则实数n 的最大值为( ) A .12 B .11 C .8 D .3 【答案】B2.(2009年黄石市)下列根式中,不是..最简二次根式的是( )ABCD 【答案】C3.(2009年邵阳市)3最接近的整数是( )A .0B .2C .4D .5 【答案】B 4.(2009年广东省)4的算术平方根是( )A .2±B .2C .D 【答案】B5.(2009贺州)下列根式中不是最简二次根式的是( ).A .2B .6C .8D . 10【答案】C 6.(2009年贵州黔东南州)下列运算正确的是( C ) A 、39±= B 、33-=- C 、39-=- D 、932=-【答案】B7.(2009年淄博市) D )A .B -CD .8.(2009年湖北省荆门市)2()x y =+,则x -y 的值为( ) A .-1 B .1 C .2 D .3解析:本题考查二次根式的意义,由题意可知1x =,1y =-,∴x -y =2,故选C . 【答案】C 9.(2009年湖北省荆门市)|-9|的平方根是( ) A .81 B .±3 C .3 D .-3解析:本题考查绝对值与平方根的运算,|-9|=9,9的平方根是±3,故选B . 【答案】B10.(2009年内蒙古包头)函数y =x 的取值范围是( )A .2x >-B .2x -≥C .2x ≠-D .2x -≤【答案】B【解析】a 的范围是0a ≥;∴y =x 的范围由20x +≥得2x ≥-。
11.(2009威海)实数a,b 在数轴上的位置如图所示,则下列结论正确的是( )A. 0a b +>B. 0a b ->C. 0a b >D .0ab>【答案】 A12.(2009的绝对值是( ) A .3B .3-C .13D .13-【答案】A13.(2009年安顺)下列计算正确的是: A =B 1= C =D .=【答案】A 14.(2009年武汉)的值是( )A .3-B .3或3-C .9D .3【答案】D15.(2009年武汉)函数y x 的取值范围是( ) A .12x -≥B .12x ≥C .12x -≤D .12x ≤【答案】B16.(2009年眉山)2的值( )A .在1到2之间B .在2到3之间C .在3到4之间D .在4到5之间【答案】C 17.(2009年常德市)28-的结果是( )A .6B .22C .2D .2【答案】C18.(2009年肇庆市)实数2-,0.3,17π-中,无理数的个数是( ) A .2 B .3 C .4 D .5 【答案】A 19.(2009 黑龙江大兴安岭)下列运算正确的是( )A .623a a a =⋅ B .1)14.3(0=-πC .2)21(1-=- D .39±=【答案】B20.(2009年黄石市)下列根式中,不是..最简二次根式的是( ) ABCD 【答案】C21.(2009年邵阳市)3最接近的整数是( )A .0B .2C .4D .5 【答案】B 22.(2009年广东省)4的算术平方根是( ) A .2± B .2C .D 【答案】B23.(2009 ( )【答案】B 24.(2009年湖北十堰市)下列运算正确的是( ). A .523=+ B .623=⨯C .13)13(2-=-D .353522-=- 【答案】B 25.(2009年茂名市)下列四个数中,其中最小..的数是( )A .0B .4-C .π-D 【答案】26.(2009 ) A .0 B .2 C .4 D .5 【答案】B27.(2009年河北)在实数范围内,x 有意义,则x 的取值范围是( ) A .x ≥0 B .x ≤0C .x >0D .x <0【答案】A28.(2009年株洲市)...,则x 的取值范围是 A . 2x ≥B .2x >C .2x <D .2x ≤【答案】A 29.(2009年台湾)若a =1.071⨯106,则a 是下列哪一数的倍数? (A) 48 (B) 64 (C) 72 (D) 81。
2009年 全国 117个地区中考试卷及答案
2009年全国各地中考试题及答案112份下载地址(截止到7月11日)(7月7日前的为红色)2009年安徽省初中毕业学业考试数学试题及答案2009年安徽省芜湖市初中毕业学业考试题及答案2009年北京高级中学中等学校招生考试数学试题及答案2009年福建省福州市课改实验区中考试卷及参考答案2009年福建省龙岩市初中毕业、升学考试试题及答案2009年福建省宁德市初中毕业、升学考试试题及答案2009年福建省莆田市初中毕业、升学考试试卷及答案2009年福建省泉州市初中毕业、升学考试试题及答案2009年福建省漳州市初中毕业暨高中阶段招生题及答案2009年甘肃省定西市中考数学试卷及答案2009年甘肃省兰州市初中毕业生学业考试试卷及答案2009年甘肃省庆阳市高中阶段学校招生考试题及答案2009年广东省佛山市高中阶段学校招生考试题及答案2009年广东省茂名市高中阶段招生考试试题及答案2009年广东省梅州市初中毕业生学业考试试题及答案2009年广东省清远市初中毕业生学业考试试题及答案2009年广东省深圳市初中毕业生学业考试试卷及答案2009年广东省肇庆市初中毕业生学业考试试题及答案2009年广西省崇左市初中毕业升学考试数学试题及答案2009年广西省桂林市百色市初中毕业暨升学试卷及答案2009年广西省河池市初中毕业暨升学统一考试卷及答案2009年广西省贺州市初中毕业升学考试试卷及答案2009年广西省柳州市初中毕业升学考试数学试卷及答案2009年广西省南宁市中等学校招生考试题及答案2009年广西省钦州市初中毕业升学考试试题卷及答案2009年广西省梧州市初中毕业升学考试卷及答案2009年贵州省安顺市初中毕业、升学招生考试题及答案2009年贵州省黔东南州初中毕业升学统一考试题及答案2009年河北省初中毕业生升学文化课考试试卷及答案2009年河南省初中学业水平暨高级中等学校招生卷及答2009年黑龙江省哈尔滨市初中升学考试题及答案2009年黑龙江省牡丹江市初中毕业学业考试题及答案2009年黑龙江省齐齐哈尔市初中毕业学业考试题及答案2009年黑龙江省绥化市初中毕业学业考试卷及答案(答案为扫描版)2009年湖北省鄂州市初中毕业及高中阶段招生题及答案2009年湖北省恩施自治州初中毕业生学业考试题及答案2009年湖北省黄冈市初中毕业生升学考试试卷及答案2009年湖北省黄石市初中毕业生学业考试联考卷及答案2009年湖北省黄石市初中毕业生学业考试试题及答案2009年湖北省十堰市初中毕业生学业考试试题及答案2009年湖北省武汉市初中毕业生学业考试试题及答案2009年湖北省襄樊市初中毕业、升学统一考试题及答案2009年湖北省孝感市初中毕业生学业考试试题及答案2009年湖北省宜昌市初中毕业生学业考试试题及答案2009年湖南省长沙市初中毕业学业考试试卷及答案2009年湖南省常德市初中毕业学业考试试题及答案2009年湖南省郴州市初中毕业考试数学试题及答案2009年湖南省衡阳市初中毕业学业考试试卷及参考答案2009年湖南省怀化市初中毕业学业考试卷及答案2009年湖南省娄底市初中毕业学业考试试题及答案2009年湖南省邵阳市初中毕业学业水平考试卷及答案2009年湖南省湘西自治州初中毕业学业考试卷及答案2009年湖南省益阳市普通初中毕业学业考试试卷及答2009年湖南省株洲市初中毕业学业考试数学试题及答案2009年吉林省长春市初中毕业生学业考试试题及答案2009年吉林省初中毕业生学业考试数学试题及答案2009年江苏省苏州市中考数学试题及答案(答案为扫描版)2009年江苏省中考数学试卷及参考答案2009年江西省中等学校招生考试数学试题及参考答案2009年辽宁省本溪市初中毕业生学业考试试题及答案2009年辽宁省朝阳市初中升学考试数学试题及答案2009年辽宁省抚顺市初中毕业生学业考试试卷及答案2009年辽宁省锦州市中考数学试题及答案2009年辽宁省铁岭市初中毕业生学业考试试题及答案2009年内蒙古赤峰市初中毕业、升学统一考试题及答案(答案为扫描版)2009年内蒙古自治区包头市高中招生考试试卷及答案2009年宁夏回族自治区初中毕业暨高中阶段招生题及答案2009年山东省德州市中等学校招生考试数学试题及答案2009年山东省东营市中等学校招生考试试题及答案2009年山东省济南市高中阶段学校招生考试试题及答案2009年山东省济宁市高中阶段学校招生考试试题及答案2009年山东省临沂市中考数学试题及参考答案2009年山东省日照市中等学校招生考试试题及参考答案2009年山东省泰安市高中段学校招生考试试题及答案2009年山东省威海市初中升学考试数学试卷及参考答案2009年山东省潍坊市初中学业水平考试数学试题及答案2009年山东省烟台市初中学生学业考试试题及答案2009年山东省枣庄市中等学校招生考试数学试题及答案2009年山东省中等学校招生考试数学试题及参考答案2009年山东省淄博市中等学校招生考试试题及答案2009年山西省初中毕业学业考试数学试卷及答案2009年山西省太原市初中毕业学业考试试卷及答案2009年陕西省初中毕业学业考试数学试题及答案2009年上海市初中毕业统一学业考试数学试卷及答案2009年四川省成都市高中学校统一招生考试试卷及答案2009年四川省达州市高中招生统一考试题及答案2009年四川省高中阶段教育学校招生统一考试题及答案2009年四川省泸州市高中阶段学校招生统一考试题及答(答案为扫描版)2009年四川省眉山市高中阶段教育学校招生试题及答案2009年四川省南充市高中阶段学校招生统一考试卷及答2009年四川省遂宁市初中毕业生学业考试试题及答案2009年台湾第一次中考数学科试题及答案2009年天津市初中毕业生学业考试数学试题及答案2009年新疆维吾尔自治区初中毕业生学业考试题及答案2009年云南省高中(中专)招生统一考试试题及答案2009年浙江省杭州市各类高中招生文化考试试题与答案2009年浙江省湖州市初中毕业生学业考试试题及答案2009年浙江省嘉兴市初中毕业生学业考试试卷及答案2009年浙江省金华市初中毕业生学业考试试卷及答案2009年浙江省丽水市初中毕业生学业考试试卷及答案2009年浙江省丽水市初中毕业生学业考试试题及答案2009年浙江省宁波市初中毕业生学业考试试题及答案2009年浙江省衢州市初中毕业生学业考试数学卷及答案2009年浙江省台州市初中学业考试数学试题及参考答案2009年浙江省温州市初中毕业生学业考试试题及答案(答案为扫描版)2009年浙江省义乌市初中毕业生学业考试题及参考答案2009年浙江省舟山市初中毕业生学业考试数学卷及答案2009年重庆市初中毕业暨高中招生考试数学试题及答案2009年重庆市江津市初中毕业学业暨高中招生试题及答2009年重庆市綦江县初中毕业暨高中招生考试题及答案。
2009年广西崇左中考数学试题及答案(word版)
2009年崇左市初中毕业升学考试数 学(全卷满分:120分;考试时间:120分钟)一、填空题:本大题共10小题;每小题2分,共20分.请将答案填写在题中的横线上. 1.5-的绝对值是 .2.已知75A ∠=°,则A ∠的余角的度数是 . 3.在函数y =x 的取值范围是 .4.分解因式:2242x x -+= .5.写出一个图像位于第一、二、三象限内的一次函数表达式: . 6.一元二次方程230x mx ++=的一个根为1-,则另一个根为 .7.已知圆锥的侧面积为28πcm ,侧面展开图的圆心角为45°,则该圆锥的母线长为cm .8.如图,点O 是O ⊙的圆心,点A B C 、、在O ⊙上,AO BC ∥,38AOB ∠=°,则OA C ∠的度数是. 9.当x ≤0时,化简1x -的结果是 .10.如图,正方形ABCD 中,E 是BC 边上一点,以E 为圆心、EC 为半径的半圆与以A 为圆心,AB 为半径的圆弧外切,则sin EAB ∠的值为 .二、选择题:本大题共8小题;每小题3分,共24分.在每小题给出的四个选项中,只有一项是正确的,请将正确答案前的字母填入题后的括号内,每小题选对得3分,选错、不选或多选均得0分.11.如图,直线c 截二平行直线a b 、,则下列式子中一定成立的是( )A .12∠=∠B .13∠=∠C .14∠=∠D .15∠=∠ 12.下列运算正确的是( )A .224236x x x =·B .22231x x -=- C .2222233x x x ÷=D .224235x x x += 13.一个等腰三角形的两边长分别为2和5,则它的周长为( ) A .7 B .9 C .12 D .9或12 14.不等式组221x x -⎧⎨-<⎩≤的整数解共有( )A .3个B .4个C .5个D .6个 15.如图,下列选项中不是..正六棱柱三视图的是( )A .B .C .D .OCBA(第8题)D C EBA(第10题) 12 3 45 abc (第11题)这组同学引体向上个数的众数与中位数依次是( )A .9和10B .9.5和10C .10和9D .10和9.5 17.如图,把矩形ABCD 沿EF 对折后使两部分重合,若150∠=°,则AEF ∠=( )A .110°B .115°C .120°D .130° 绕点O 按逆时18.已知点A 的坐标为()a b ,,O 为坐标原点,连结OA ,将线段OA 针方向旋转90°得1OA ,则点1A 的坐标为( )A .()a b -,B .()a b -,C .()b a -,D .()b a -, 三、解答题:本大题共7小题,共76分. 19.(本小题满分6分)计算:0200912sin 603tan30(1)3⎛⎫-++- ⎪⎝⎭°°.20.(本小题满分8分)已知220x -=,求代数式222(1)11x x x x -+-+的值.21.(本小题满分10分)如图,ABC △中,D E 、分别是边BC AB 、的中点,AD CE 、相交于G .求证:13GE GD CEAD ==.1 A ED CB F(第17题)BCDGEA (第21题)22.(本小题满分10分)一只口袋中放着若干只红球和白球,这两种球除了颜色以外没有任何其他区别,袋中的球已经搅匀,蒙上眼睛从口袋中取出一只球,取出红球的概率是14. (1)取出白球的概率是多少?(2)如果袋中的白球有18只,那么袋中的红球有多少只?23.(本小题满分12分)五一期间某校组织七、八年级的同学到某景点郊游,该景点的门票全票票价为15元/人,若为50~99人可以八折购票,100人以上则可六折购票.已知参加郊游的七年级同学少于50人,八年级同学多于50人而少于100人.若七、八年级分别购票,两个年级共计应付门票费1575元,若合在一起购买折扣票,总计应付门票费1080元.问:(1)参加郊游的七、八年级同学的总人数是否超过100人? (2)参加郊游的七、八年级同学各为多少人?24.(本小题满分14分)如图,在等腰梯形ABCD 中,已知AD BC ∥,24AB DC AD BC ===,,,延长BC 到E ,使C E A D =.(1)证明:BAD DCE △≌△;(2)如果AC BD ⊥,求等腰梯形ABCD 的高DF 的值. DABEF (第24题)25.(本小题满分16分)在平面直角坐标系中,现将一块等腰直角三角板ABC 放在第二象限,斜靠在两坐标轴上,且点(02)A ,,点(10)C -,,如图所示:抛物线22y ax ax =+-经过点B .(1)求点B 的坐标; (2)求抛物线的解析式;(3)在抛物线上是否还存在点P (点B 除外),使ACP △仍然是以AC 为直角边的等腰直角三角形?若存在,求所有点P 的坐标;若不存在,请说明理由.2009年崇左市初中毕业升学考试数 学 答 案一、1.5 2.15° 3.3x -≥ 4.22(1)x - 5.1y x =+等6.3- 7.8 8.19° 9.1 10.35二、11.B 12.A 13.C 14.C 15A 16.D 17.B 18.C 三、19.原式=2311-- ················································································· 4分 =0. ················································································································· 6分20.原式=22(1)(1)(1)1x x x x x -+-++ ···························································································· 2分 =2111x x x x -+++········································································································ 4分 =211x x x +-+············································································································ 5分(第25题)220x -=, 22x ∴= ··············································································································· 6分∴原式211x x +-=+··································································································· 7分 ∴原式=1 ················································································································· 8分 21.证明:连结ED , ······························································ 1分 D E 、分别是边BC AB 、的中点,12DE DE AC AC ∴=∥,, ··························································· 3分 ACG DEG ∴△∽△, ····························································· 5分12GE GD DE GC AG AC ∴===, ······················································· 7分13GE GD CE AD ∴==. ············································································································· 10分 22.(1)()()P 1P =-取出白球取出红球 ························································································· 3分=13144-= ····························································································································· 4分 (2)设袋中的红球有x 只,则有 ························································································· 5分 1184x x =+ (或183184x =+) ······················································································· 8分 解得6x =所以,袋中的红球有6只. ································································································ 10分 23.(1)全票为15元,则八折票价为12分,六折票价为9元. ······································ 2分1001515001575⨯=< ····································································································· 4分∴参加郊游的七、八年级同学的总人数必定超过100人. ················································· 5分 (2)设七、八年级参加郊游的同学分别有x 人、y 人 ······················································· 6分由(1)及已知,5050100100x y x y <<<+>,,. ······················································· 7分 依题意可得:151215759()1080x y x y +=⎧⎨+=⎩·············································································································· 10分 解得4575x y =⎧⎨=⎩ ································································································································ 11分 答:参加郊游的七、八年级同学分别为45人和75人. ··················································· 12分24.(1)证明:AD BC CDA DCE ∴∠=∠∥,. ·························································· 1分 又四边形ABCD 是等腰梯形,BAD CDA ∴∠=∠, ···················································· 2分 BAD DCE ∴∠=∠. ··········································································································· 3分 AB DC AD CE ==,, BAD DCE ∴△≌△. ········································································································· 5分(2)AD CE AD BC =∴,∥,四边形ACED 是平行四边形, ····································· 7分B C D GEAAC DE ∴∥. ······················································································································ 8分 AC BD DE BD ⊥∴⊥,. ································································································ 9分 由(1)可知,BAD DCE △≌△,DE BD ∴=. ························································ 10分 所以,BDE △是等腰直角三角形,即45E ∠=°, DF FE FC CE ∴==+. ································································································· 12分 四边形ABCD 是等腰梯形,而24AD BC ==,, 1FC ∴=. ·························································································································· 13分 2CE AD == 3DF ∴=. ························································································································· 14分 25.(1)过点B 作BD x ⊥轴,垂足为D , 9090BCD ACO ACO CAO ∠+∠=∠+∠=°,° BCD CAO ∴∠=∠; ····················································· 1分 又90BDC COA CB AC ∠=∠==°;, BCD CAO ∴△≌△, ···················································· 2分12BD OC CD OA ∴====, ····································· 3分 ∴点B 的坐标为(31)-,; ················································ 4分 (2)抛物线22y ax ax =+-经过点(31)B -,,则得到19a =-解得12a =,所以抛物线的解析式为211222y x x =+-; ················································· 7分 (3)假设存在点P ,使得ACP △仍然是以AC 为直角边的等腰直角三角形: ①若以点C 为直角顶点;则延长BC 至点1P ,使得1PC BC =,得到等腰直角三角形1ACP △, ···························· 8分 过点1P 作1PM x ⊥轴, 11190CP BC MCP BCD PMC BDC =∠=∠∠=∠=,,°; 1MPC DBC ∴△≌△ ·········································································································· 10分 121CM CD PM BD ∴====,,可求得点1P (1,-1); ·············································· 11分 ②若以点A 为直角顶点;则过点A 作2AP CA ⊥,且使得2AP AC =,得到等腰直角三角形2ACP △, ·············· 12分 过点2P 作2P N y ⊥轴,同理可证2AP N CAO △≌△; ·················································· 13分 221NP OA AN OC ∴====,,可求得点2(21)P ,; ···················································· 14分 经检验,点1(11)P -,与点2(21)P ,都在抛物线211222y x x =+-上. ····························· 16分。
2009年中考数学试题分类汇编2 无理数及二次根式(含答案)
2009年中考数学试题分类汇编2无理数及二次根式一、选择题.(2009年绵阳市)已知n −12是正整数,则实数n 的最大值为()A .12B .11C .8D .3【答案】B.(2009年黄石市)下列根式中,不是..最简二次根式的是()A B C D 【答案】C.(2009年邵阳市)3最接近的整数是()A .0B .2C .4D .5【答案】B .(2009年广东省)4的算术平方根是()A .2±B .2C .D 【答案】B.(2009贺州)下列根式中不是最简二次根式的是().A .2B .6C .8D .10【答案】C.(2009年贵州黔东南州)下列运算正确的是(C )A、39±=B、33−=−C、39−=−D、932=−【答案】B.(2009年淄博市)计算D)A .B −CD ..(2009年湖北省荆门市)若2()x y =+,则x -y 的值为()A .-1B .1C .2D .3解析:本题考查二次根式的意义,由题意可知1x =,1y =−,∴x -y =2,故选C .【答案】C .(2009年湖北省荆门市)|-9|的平方根是()A .81B .±3C .3D .-3解析:本题考查绝对值与平方根的运算,|-9|=9,9的平方根是±3,故选B .【答案】B.(2009年内蒙古包头)函数y =x 的取值范围是()A .2x >−B .2x −≥C .2x ≠−D .2x −≤【答案】B【解析】a 的范围是0a ≥;∴y =中x 的范围由20x +≥得2x ≥−。
.(2009威海)实数a,b 在数轴上的位置如图所示,则下列结论正确的是()A.0a b +>B.0a b −>C.0a b > D.0ab>01【答案】A.(2009威海)的绝对值是()A.3B.3−C.13D.13−【答案】A.(2009年安顺)下列计算正确的是:A −=B 1=C =D .=【答案】A.(2009年武汉)二次根式)A.3−B.3或3−C.9D.3【答案】D.(2009年武汉)函数y =x 的取值范围是()A.12x −≥B.12x ≥C.12x −≤D.12x ≤【答案】B.(2009年眉山)估算2的值()A.在1到2之间B.在2到3之间C.在3到4之间D.在4到5之间【答案】C.(2009年常德市)28−的结果是()A .6B .22C .2D .2【答案】C.(2009年肇庆市)实数2−,0.3,17,,π−中,无理数的个数是()A .2B .3C .4D .5【答案】A .(2009黑龙江大兴安岭)下列运算正确的是()A .623a a a =⋅B .1)14.3(0=−πC .2)21(1−=−D .39±=【答案】B.(2009年黄石市)下列根式中,不是..最简二次根式的是()A B C D 【答案】C.(2009年邵阳市)3最接近的整数是()A .0B .2C .4D .5【答案】B .(2009年广东省)4的算术平方根是()A .2±B .2C .D 【答案】B.(2009化简的结果是()A.2B.C .−D .±【答案】B .(2009年湖北十堰市)下列运算正确的是().A .523=+B .623=×C .13)13(2−=−D .353522−=−.(2009年茂名市)下列四个数中,其中最小..的数是()A .0B .4−C .π−D 【答案】.(2009湖南邵阳))A .0B .2C .4D .5【答案】B .(2009年河北)在实数范围内,x 有意义,则x 的取值范围是()A .x ≥0B .x ≤0C .x >0D .x <0【答案】A.(2009年株洲市)若使二次根式在实数范围内有意义...,则x 的取值范围是A .2x ≥B .2x >C .2x <D .2x ≤【答案】A .(2009年台湾)若a =1.071×106,则a 是下列哪一数的倍数?(A)48(B)64(C)72(D)81。
2009年广西柳州市中考数学试题及答案(含参考答案和评分标准)
数 学(考试时间共120分钟,全卷满分120分)第Ⅰ卷(选择题,共18分)注意事项:1.答题前,考生务必先将自己的姓名、准考证号用蓝、黑色墨水笔或圆珠笔填写在试卷左边的密封线内. 2.第Ⅰ卷为第1页至第二页.答题时,请用2B 铅笔把各小题正确答案序号填涂在答题卡对应的题号内.如需改动,须用橡皮擦干净后,再填涂其它答案. 在第Ι卷上答题无效.一、选择题(本大题共6小题,每小题3分,满分18分.在每个小题给出的四个选项中,只有一项是正确的,每小题选对得3分,选错、不选或多选均得零分)1.在3,0,2-,2四个数中,最小的数是( ) A .3 B .0 C .2- D .2 2.如图1所示,图中三角形的个数共有( ) A .1个 B .2个 C .3 个 D .4个 3.若b a <,则下列各式中一定成立的是( )A .11-<-b aB .33ba >C . b a -<-D . bc ac <4.某学习小组7个男同学的身高(单位:米)为:1.66、1.65、1.72、1.58、1.64、1.66、1.70,那么这组数据的众数为( )A .1.65B .1.66C .1.67D .1.70 5.分式方程3221+=x x 的解是( ) A .0=x B .1=x C .2=x D .3=x6.一根笔直的小木棒(记为线段AB ),它的正投影为线段CD ,则下列各式中一定成立的是( ) A .AB=CD B .AB ≤CD C .CD AB > D .AB ≥CDCD BA图1数 学注意事项:1.答题前,考生务必先将自己的姓名、准考证号用蓝、黑色墨水笔或圆珠笔填写在试卷左边的密封线内.2.第Ⅱ卷从第3页至第10页.答题时,用蓝、黑色墨水笔或圆珠笔直接将答案写在试卷上.第Ⅱ卷(非选择题,满分102分)二、填空题(本大题共10小题,每小题3分,满分30分. 请将答案直接填写在题中横线上的空白处)7.计算:2)5(0+-= .8.请写出一个是轴对称图形的图形名称.答: . 9.计算:312-= .10.在图2中,直线AB ∥CD ,直线EF 与AB 、CD 分别相交于点E 、F , 如果∠1=46°,那么∠2= °.11.一个物体现在的速度是5米/秒,其速度每秒增加2米/秒,则再过 秒它的速度为15米/秒. 12.因式分解:22x x -= . 13.反比例函数 xm y 1+=的图象经过点(2,1),则m 的值是 . 14.在一个不透明的口袋中装有若干个只有颜色不同的球,如果已知袋中只有4个红球,且摸出红球的概率为31,那么袋中的球共有 个. 15.如图3,︒=∠30MAB ,P 为AB 上的点,且6=AP ,圆P与AM 相切,则圆P 的半径为 .16.矩形内有一点P 到各边的距离分别为1、3、5、7,则该矩形的最大面积为 平方单位. 三、解答题(本大题10小题,满分72分.解答应写出必要的文字说明、演算步骤或推理过程)得 分 评卷员图3FED C BA2 1 图217.(本题满分6分)先化简,再求值:)5()1(3---x x ,其中2=x .18.(本题满分6分) 解不等式组⎩⎨⎧>+<+②392① 31x x ,并把它的解集表示在数轴上.19.(本题满分6分)某学习小组对所在城区初中学生的视力情况进行抽样调查,图4是这些同学根据调查结果画出的条形统计图.请根据图中信息解决下列问题:(1)本次抽查活动中共抽查了多少名学生?(2)请估算该城区视力不低于4.8的学生所占的比例,用扇形统计图在图5中表示出来. (3)假设该城区八年级共有4000名学生,请估计这些学生中视力低于4.8的学生约有多少人?20.(本题满分6分)如图6,四边形ABCD 中,AB ∥CD ,∠B=∠D ,3 ,6==AB BC ,求四边得 分 评卷员得 分 评卷员得 分 评卷员得 分 评卷员2图5图4形ABCD 的周长. 21.(本题满分6分)如图6,正方形网格中,△ABC 为格点三角形(顶点都是格点),将△ABC 绕点A 按逆时针方向旋转90°得到11AB C △.(1)在正方形网格中,作出11AB C △;(不要求写作法) (2)设网格小正方形的边长为1cm ,用阴影表示出旋转过程中线段BC 所扫过的图形,然后求出它的面积.(结果保留π)22.(本题满分6分)如图8,热气球的探测器显示,从热气球看一栋高楼顶部的仰角为︒60,看这栋高楼底部的俯角为︒30,热气球与高楼的水平距离为66 m ,这栋高楼有多高?(结果精确到0.1 m ,参考数据:73.13≈) 23.(本题满分8分)如图9, 直线l 与x 轴、y 轴分别交于点) 0,8 ( M ,点) 6,0 ( N .点P 从点N 出发,以每秒1个单位长度的速度沿N →O 方向运动,点Q从点O 出发,以每秒2个单位长度的速得 分 评卷员得 分 评卷员得 分 评卷员C AB图8BCA 图7度沿O →M 的方向运动.已知点QP 、同时出发,当点Q到达点M 时,QP 、两点同时停止运动, 设运动时间为t 秒.(1)设四边形...MNPQ 的面积为S ,求S 关于t 的函数关系式,并写出t 的取值范围. (2)当t 为何值时,QP 与l 平行? 24.(本题满分8分)某校积极推进“阳光体育”工程,本学期在九年级11个班中开展篮球单循环比赛(每个班与其它班分别进行一场比赛,每班需进行10场比赛).比赛规则规定:每场比赛都要分出胜负,胜一场得3分,负一场得1-分.(1)如果某班在所有的比赛中只得14分,那么该班胜负场数分别是多少?(2)假设比赛结束后,甲班得分是乙班的3倍,甲班获胜的场数不超过5场,且甲班获胜的场数多于乙班,请你求出甲班、乙班各胜了几场.25.(本题满分10分)如图10,AB 是⊙O 的直径,C 是弧BD 的中点,CE ⊥AB ,垂足为E ,BD 交CE 于点F .(1)求证:CF BF =;得 分 评卷员得 分 评卷员图9(2)若2AD =,⊙O 的半径为3,求BC 的长.26.(本题满分10分)如图11,已知抛物线b ax ax y --=22(0>a )与x 轴的一个交点为(10)B -,,与y 轴的负半轴交于点C ,顶点为D .(1)直接写出抛物线的对称轴,及抛物线与x 轴的另一个交点A 的坐标; (2)以AD 为直径的圆经过点C . ①求抛物线的解析式;②点E 在抛物线的对称轴上,点F 在抛物线上,且以E F A B ,,,四点为顶点的四边形为平行四边形,求点F 的坐标.2009年柳州市初中毕业升学考试数学参考答案及评分标准第Ⅰ卷:一、选择题得 分 评 卷 员图11第Ⅱ卷:二、填空题三、解答题:17. 本小题满分6分.解:原式=533+--x x ········································································································ 2分=22+x ·············································································································· 4分 当2=x 时,原式=222+⨯ ··················································································· 5分=6 ···························································································· 6分(说明:如果直接求值,没有进行化简,结果正确扣1分) 18. 本小题满分6分.解: 由①得:13-<x ··································································································· 1分即2<x ····································································································· 2分 由②得:62->x ······························································································ 3分即3->x ······························································································ 4分 ∴原不等式的解集为23<<-x ·············································································· 5分 在数轴上表示为:····························· 6分19. 本小题满分6分.解:(1)本次抽查活动中共抽查了2100名学生. ······························································ 2分;(2)本次抽查中视力不低于4.8的学生人数为1400人,比例为32,约占67%.所以该城区视力不低于4.8的学生约占67%.扇形统计图表示为:………………………………4分(说明:图中只要标对扇形圆心角为240°,或标明所占比例正确的,都不扣分)(3)抽查知在八年级的学生中,视力低于4.8的学生所占比例为800300,则该城区八年级视力低于4.82图5阴影部分为视力不低于 4.8人数,占32,约67%的学生人数约为:150********300=⨯人. ········································································· 6分 20、本小题满分6分.解法一: ∵AB CD ∥∴︒=∠+∠180C B ························································ 1分 又∵B D ∠=∠∴︒=∠+∠180D C ···················································· 2分 ∴AD ∥BC 即得ABCD 是平行四边形 ······················· 4分 ∴36AB CD BC AD ====, ·································· 5分 ∴四边形ABCD 的周长183262=⨯+⨯= ·················· 6分 解法二: 连接AC ···································································· 1分∵AB CD ∥∴DCA BAC ∠=∠ ······················································· 2分 又∵B D AC CA ∠=∠=, ············································· 3分 ∴ABC △≌CDA △ ······················································· 4分 ∴36AB CD BC AD ====, ···································· 5分 ∴四边形ABCD 的周长183262=⨯+⨯= ·················· 6分 解法三: 连接BD ····································································· 1分∵AB CD ∥∴CDB ABD ∠=∠ ························································· 2分 又∵ABC CDA ∠=∠ ∴ADB CBD ∠=∠ ························································· 3分 ∴AD ∥BC 即ABCD 是平行四边形 ···························· 4分 ∴36AB CD BC AD ====, ······································ 5分 ∴四边形ABCD 的周长183262=⨯+⨯= ····················6分 (没有经过证明而直接写出结果的给2分,其它解法参照给分) 21.解:( AD CB图6AD CB图6AD CB图6解:如图8,过点A 作BC AD ⊥,垂足为D根据题意,可得︒=∠60BAD ,︒=∠30CAD ,66=AD ······································ 1分在Rt △ADB 中,由ADBD BAD =∠tan得36636660tan 66tan =⨯=︒⨯=∠⋅=BAD AD BD . ····· 3分 在Rt △ADC 中,由ADCDCAD =∠tan 得322336630tan 66tan =⨯=︒⨯=∠⋅=CAD AD CD . ·································· 5分 ∴152.2BC BD CD =+==. ·············································· 6分 答:这栋楼高约为152.2 m . (其它解法参照给分) 23、本小题满分8分.解:(1)依题意,运动总时间为428==t 秒,要形成四边形MNPQ ,则运动时间为40<<t . 1分 当P 点在线段NO 上运动t 秒时,t OQ t OP 2 ,6=-=∴12POQ S OP OQ =⋅△=t t 62+- ················· 2分 此时四边形MNPQ 的面积MON POQ S S S =-△△=)6(68212t t +--⨯⨯ =2462+-t t ································································································· 4分∴S 关于t 的函数关系式为2624(04)S t t t =-+<<, ·········································· 5分(2)当PQ 与l 平行时,NOM △∽POQ △ ································································· 6分PO NO QO MO = 即 tt -=6628 ··················································································· 7分 ∴2410=t ,即4.2=t∴当4.2=t 秒时, PQ 与l 平行. ··········································································· 8分 (其它解法参照给分)DCAB图8图9解: (1)设该班胜x 场,则该班负)10(x -场. ······························································· 1分依题意得: 14)10(3=--x x ··········································································· 2分 解之得: 6=x ···························································································· 3分所以该班胜6场,负4场. ·················································································· 4分 (2)设甲班胜了x 场,乙班胜了y 场,依题意有:)]10(3[3)10(3y y x x --=-- ······································································ 5分 化简得:53+=x y 即35+=x y ··································································································· 6分 由于y x , 是非负整数,且05x ≤≤,y x >∴4=x ,3=y .所以甲班胜4场,乙班胜3场. ··········································································· 8分 答:(1)该班胜6场,负4场.(2)甲班胜4场,乙班胜3场. (其它解法参照给分) 25、本小题满分10分.证明:(1) 连结AC ,如图10 ∵C 是弧BD 的中点∴∠BDC =∠DBC ··············································· 1分又∠BDC =∠BAC在三角形ABC 中,∠ACB =90°,CE ⊥AB∴ ∠BCE=∠BAC ∠BCE =∠DBC ············································· 3分 ∴ CF =BF ······················································ 4分 因此,CF =BF .(2)证法一:作CG ⊥AD 于点G ,∵C 是弧BD 的中点∴ ∠CAG =∠BAC , 即AC 是∠BAD 的角平分线.············································ 5分 ∴ CE =CG ,AE =AG ···························································································· 6分 在Rt △BCE 与Rt △DCG 中,CE =CG , CB =CD ∴Rt △BCE ≌Rt △DCG ∴BE =DG ·············································································································· 7分 ∴AE =AB -BE =AG =AD +DG 即 6-BE =2+DG∴2BE =4,即 BE =2 ··························································································· 8分又 △BCE ∽△BAC∴ 212BC BE AB ==· ····················································································· 9分B 图1032±=BC (舍去负值)∴32=BC ··································································································· 10分 (2)证法二:∵AB 是⊙O 的直径,CE ⊥AB ∴∠BEF=︒=∠90ADB , ······························· 5分 在Rt ADB △与Rt FEB △中, ∵FBE ABD ∠=∠∴ADB △∽FEB △,则BFABEF AD =即BFEF 62=, ∴EF BF 3= ···················· 6分 又∵CF BF =, ∴EF CF 3=利用勾股定理得:EF EF BF BE 2222=-= ······································································· 7分又∵△EBC ∽△ECA 则CEBE AE CE =,即则BE AE CE ⋅=2································································ 8分 ∴BE BE EF CF ⋅-=+)6()(2即EF EF EF EF 22)226()3(2⋅-=+∴22=EF ···································································································· 9分 ∴3222=+=CE BE BC ········································································· 10分26、本小题满分10分. 解:(1)对称轴是直线:1=x , 点A 的坐标是(3,0). ································································· 2分 (说明:每写对1个给1分,“直线”两字没写不扣分) (2)如图11,连接AC 、AD ,过D 作轴 y DM ⊥于点M , 解法一:利用AOC CMD △∽△∵点A 、D 、C 的坐标分别是A (3,0),D (1,b a --)、 C (0,b -),∴AO =3,MD =1.由MD OC CM AO =得13ba = ∴03=-ab ··································································································· 3分又∵b a a --⋅--⋅=)1(2)1(02···································································· 4分图11B图10。
2009年广西桂林市百色市中考数学试题及答案-推荐下载
20.(本题满分 6 分)先化简,再求值: 1 1 (x2 y2 x y ) ,
其中 x 2,y 3 .
2x x y
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最新 广西崇左市初三中考数学试卷
广西崇左市中考数学试卷一、选择题(本大题共12小题,每小题3分,共36分)1.(3分)下列四个数中最大的数是()A.0 B.﹣1 C.﹣2 D.﹣32.(3分)如图,直线a,b被c所截,则∠1与∠2是()A.同位角 B.内错角C.同旁内角D.邻补角3.(3分)一天时间为86400秒,用科学记数法表示这一数字是()A.864×102B.86.4×103C.8.64×104D.0.864×1054.(3分)一组数据:6,3,4,5,7的平均数和中位数分别是()A.5,5 B.5,6 C.6,5 D.6,65.(3分)下列运算正确的是()A.(a3)2=a5B.a2•a3=a5 C.a6÷a2=a3D.3a2﹣2a2=16.(3分)如图所示的几何体的俯视图是()A.B.C. D.7.(3分)五星红旗上的每一个五角星()A.是轴对称图形,但不是中心对称图形B.是中心对称图形,但不是轴对称图形C.既是轴对称图形,又是中心对称图形D.既不是轴对称图形,也不是中心对称图形8.(3分)对于函数y=﹣2(x﹣m)2的图象,下列说法不正确的是()A.开口向下B.对称轴是x=m C.最大值为0 D.与y轴不相交9.(3分)如图,在矩形ABCD中,AB>BC,点E,F,G,H分别是边DA,AB,BC,CD 的中点,连接EG,HF,则图中矩形的个数共有()A.5个B.8个C.9个D.11个10.(3分)如图,一艘轮船在A处测得灯塔P位于其北偏东60°方向上,轮船沿正东方向航行30海里到达B处后,此时测得灯塔P位于其北偏东30°方向上,此时轮船与灯塔P的距离是()A.15海里B.30海里 C.45海里 D.30海里11.(3分)如图,大小不同的两个磁块,其截面都是等边三角形,小三角形边长是大三角形边长的一半,点O是小三角形的内心,现将小三角形沿着大三角形的边缘顺时针滚动,当由①位置滚动到④位置时,线段OA绕点O顺时针转过的角度是()A.240°B.360°C.480°D.540°12.(3分)如图,AB是⊙O的直径,AC,BC分别与⊙O相交于点D,E,连接DE,现给出两个命题:①若AC=AB,则DE=CE;②若∠C=45°,记△CDE的面积为S1,四边形DABE的面积为S2,则S1=S2,那么()A.①是真命题②是假命题B.①是假命题②是真命题C.①是假命题②是假命题D.①是真命题②是真命题二、填空题(本大题共6小题,每小题3分,共18分)13.(3分)|﹣1|= .14.(3分)若4a2b2n+1与a m b3是同类项,则m+n= .15.(3分)分解因式:a3﹣ab2= .16.(3分)如图是小强根据全班同学喜爱四类电视节目的人数而绘制的两幅不完整的统计图,则喜爱“体育”节目的人数是人.17.(3分)如图,在边长为2的正八边形中,把其不相邻的四条边均向两边延长相交成一个四边形ABCD,则四边形ABCD的周长是.18.(3分)已知抛物线:y=ax2+bx+c(a>0)经过A(﹣1,1),B(2,4)两点,顶点坐标为(m,n),有下列结论:①b<1;②c<2;③0<m<;④n≤1.则所有正确结论的序号是.三、解答题(本大题共8小题,共66分)19.(6分)计算:(﹣π)0+﹣2tan45°.20.(6分)化简:(a+1﹣)÷,然后给a从1,2,3中选取一个合适的数代入求值.21.(6分)已知关于x的一元二次方程:x2﹣(t﹣1)x+t﹣2=0.(1)求证:对于任意实数t,方程都有实数根;(2)当t为何值时,方程的两个根互为相反数?请说明理由.22.(8分)在一个不透明的袋子中有一个黑球a和两个白球b,c(除颜色外其他均相同).用树状图(或列表法)解答下列问题:(1)小丽第一次从袋子中摸出一个球不放回,第二次又从袋子中摸出一个球.则小丽两次都摸到白球的概率是多少?(2)小强第一次从袋子中摸出一个球,摸到黑球不放回,摸到白球放回;第二次又从袋子中摸出一个球,则小强两次都摸到白球的概率是多少?23.(9分)如图,AB是⊙O的直径,AC是上半圆的弦,过点C作⊙O的切线DE交AB 的延长线于点E,过点A作切线DE的垂线,垂足为D,且与⊙O交于点F,设∠DAC,∠CEA 的度数分别是α,β.(1)用含α的代数式表示β,并直接写出α的取值范围;(2)连接OF与AC交于点O′,当点O′是AC的中点时,求α,β的值.24.(9分)某新建成学校举行美化绿化校园活动,九年级计划购买A,B两种花木共100棵绿化操场,其中A花木每棵50元,B花木每棵100元.(1)若购进A,B两种花木刚好用去8000元,则购买了A,B两种花木各多少棵?(2)如果购买B花木的数量不少于A花木的数量,请设计一种购买方案使所需总费用最低,并求出该购买方案所需总费用.25.(10分)如图,在等腰直角三角形ABC中,∠ACB=90°,AC=BC=4,D是AB的中点,E,F分别是AC,BC上的点(点E不与端点A,C重合),且AE=CF,连接EF并取EF 的中点O,连接DO并延长至点G,使GO=OD,连接DE,DF,GE,GF.(1)求证:四边形EDFG是正方形;(2)当点E在什么位置时,四边形EDFG的面积最小?并求四边形EDFG面积的最小值.26.(12分)如图,一次函数y=k1x+5(k1<0)的图象与坐标轴交于A,B两点,与反比例函数y=(k2>0)的图象交于M,N两点,过点M作MC⊥y轴于点C,已知CM=1.(1)求k2﹣k1的值;(2)若=,求反比例函数的解析式;(3)在(2)的条件下,设点P是x轴(除原点O外)上一点,将线段CP绕点P按顺时针或逆时针旋转90°得到线段PQ,当点P滑动时,点Q能否在反比例函数的图象上?如果能,求出所有的点Q的坐标;如果不能,请说明理由.广西崇左市中考数学试卷参考答案与试题解析一、选择题(本大题共12小题,每小题3分,共36分)1.(3分)(•玉林)下列四个数中最大的数是()A.0 B.﹣1 C.﹣2 D.﹣3【解答】解:∵0>﹣1>﹣2>﹣3,∴最大的数是0,故选A2.(3分)(•玉林)如图,直线a,b被c所截,则∠1与∠2是()A.同位角 B.内错角C.同旁内角D.邻补角【解答】解:如图所示,两条直线a、b被直线c所截形成的角中,∠1与∠2都在a、b直线的之间,并且在直线c的两旁,所以∠1与∠2是内错角.故选:B.3.(3分)(•玉林)一天时间为86400秒,用科学记数法表示这一数字是()A.864×102B.86.4×103C.8.64×104D.0.864×105【解答】解:86400=8.64×104.故选:C.4.(3分)(•玉林)一组数据:6,3,4,5,7的平均数和中位数分别是()A.5,5 B.5,6 C.6,5 D.6,6【解答】解:平均数为:×(6+3+4+5+7)=5,按照从小到大的顺序排列为:3,4,5,6,7,所以,中位数为:5.故选A.5.(3分)(•玉林)下列运算正确的是()A.(a3)2=a5B.a2•a3=a5 C.a6÷a2=a3D.3a2﹣2a2=1 【解答】解:A、错误.(a3)2=a6.B、正确.a2•a3=a5.C、错误.a6÷a2=a4.D、错误.3a2﹣2a2=a2,故选B.6.(3分)(•玉林)如图所示的几何体的俯视图是()A.B.C. D.【解答】解:从上往下看该几何体的俯视图是D.故选D.7.(3分)(•玉林)五星红旗上的每一个五角星()A.是轴对称图形,但不是中心对称图形B.是中心对称图形,但不是轴对称图形C.既是轴对称图形,又是中心对称图形D.既不是轴对称图形,也不是中心对称图形【解答】解:∵五星红旗上的五角星是等腰三角形,∴五星红旗上的每一个五角星是轴对称图形,但不是中心对称图形.故选A.8.(3分)(•玉林)对于函数y=﹣2(x﹣m)2的图象,下列说法不正确的是()A.开口向下B.对称轴是x=m C.最大值为0 D.与y轴不相交【解答】解:对于函数y=﹣2(x﹣m)2的图象,∵a=﹣2<0,∴开口向下,对称轴x=m,顶点坐标为(m,0),函数有最大值0,故A、B、C正确,故选D.9.(3分)(•玉林)如图,在矩形ABCD中,AB>BC,点E,F,G,H分别是边DA,AB,BC,CD的中点,连接EG,HF,则图中矩形的个数共有()A.5个B.8个C.9个D.11个【解答】解:∵E,G分别是边DA,BC的中点,四边形ABCD是矩形,∴四边形DEGC、AEGB是矩形,同理四边形ADHF、BCHF是矩形,则图中四个小四边形是矩形,故图中矩形的个数共有9个,故选:C.10.(3分)(•玉林)如图,一艘轮船在A处测得灯塔P位于其北偏东60°方向上,轮船沿正东方向航行30海里到达B处后,此时测得灯塔P位于其北偏东30°方向上,此时轮船与灯塔P的距离是()A.15海里B.30海里 C.45海里 D.30海里【解答】解:作BD⊥AP,垂足为D.根据题意,得∠BAD=30°,BD=15海里,∴∠PBD=60°,则∠DPB=30°,BP=15×2=30(海里),故选:B.11.(3分)(•玉林)如图,大小不同的两个磁块,其截面都是等边三角形,小三角形边长是大三角形边长的一半,点O是小三角形的内心,现将小三角形沿着大三角形的边缘顺时针滚动,当由①位置滚动到④位置时,线段OA绕点O顺时针转过的角度是()A.240°B.360°C.480°D.540°【解答】解:由题意可得:第一次AO顺时针转动了120°,第二次AO顺时针转动了240°,第三次AO顺时针转动了120°,故当由①位置滚动到④位置时,线段OA绕点O顺时针转过的角度是:120°+240°+120°=480°.故选:C.12.(3分)(•玉林)如图,AB是⊙O的直径,AC,BC分别与⊙O相交于点D,E,连接DE,现给出两个命题:①若AC=AB,则DE=CE;②若∠C=45°,记△CDE的面积为S1,四边形DABE的面积为S2,则S1=S2,那么()A.①是真命题②是假命题B.①是假命题②是真命题C.①是假命题②是假命题D.①是真命题②是真命题【解答】解:∵AC=AB,∴∠C=∠B,∵四边形ABED内接于⊙O,∴∠B=∠CDE,∴∠C=∠CDE,∴DE=CE;①正确;连接AE,∵AB是⊙O的直径,∴∠AEC=90°,又∠C=45°,∴AC=CE,∵四边形ABED内接于⊙O,∴∠B=∠CDE,∠CAB=∠CED,∴△CDE∽△CBA,∴=()2=,∴S1=S2,②正确,故选:D.二、填空题(本大题共6小题,每小题3分,共18分)13.(3分)(•玉林)|﹣1|= 1 .【解答】解:|﹣1|=1.故答案为:1.14.(3分)(•玉林)若4a2b2n+1与a m b3是同类项,则m+n= 3 .【解答】解:∵4a2b2n+1与a m b3是同类项,∴,∴,∴m+n=3,故答案为3.15.(3分)(•玉林)分解因式:a3﹣ab2= a(a+b)(a﹣b).【解答】解:a3﹣ab2=a(a2﹣b2)=a(a+b)(a﹣b).故答案为:a(a+b)(a﹣b).16.(3分)(•玉林)如图是小强根据全班同学喜爱四类电视节目的人数而绘制的两幅不完整的统计图,则喜爱“体育”节目的人数是10 人.【解答】解:5÷10%=50(人),50×30%=15(人),50﹣5﹣15﹣20=10(人).答:喜爱“体育”节目的人数是10人.故答案为:10.17.(3分)(•玉林)如图,在边长为2的正八边形中,把其不相邻的四条边均向两边延长相交成一个四边形ABCD,则四边形ABCD的周长是8+8.【解答】解:由题意可得,AD=2+×2=2+2,∴四边形ABCD的周长是:4×(2+2)=8+8,故答案为:8+8.18.(3分)(•玉林)已知抛物线:y=ax2+bx+c(a>0)经过A(﹣1,1),B(2,4)两点,顶点坐标为(m,n),有下列结论:①b<1;②c<2;③0<m<;④n≤1.则所有正确结论的序号是①②④.【解答】解:∵抛物线过点A(﹣1,1),B(2,4),∴,∴b=﹣a+1,c=﹣2a+2.∵a>0,∴b<1,c<2,∴结论①②正确;∵抛物线的顶点坐标为(m,n),∴m=﹣=﹣=﹣,∴m<,结论③不正确;∵抛物线y=ax2+bx+c(a>0)经过A(﹣1,1),顶点坐标为(m,n),∴n≤1,结论④正确.综上所述:正确的结论有①②④.故答案为:①②④.三、解答题(本大题共8小题,共66分)19.(6分)(•玉林)计算:(﹣π)0+﹣2tan45°.【解答】解:(﹣π)0+﹣2tan45°=1+2﹣2×1=120.(6分)(•玉林)化简:(a+1﹣)÷,然后给a从1,2,3中选取一个合适的数代入求值.【解答】解:原式=•=•=2(a+2)=2a+4,当a=3时,原式=6+4=10.21.(6分)(•玉林)已知关于x的一元二次方程:x2﹣(t﹣1)x+t﹣2=0.(1)求证:对于任意实数t,方程都有实数根;(2)当t为何值时,方程的两个根互为相反数?请说明理由.【解答】(1)证明:在方程x2﹣(t﹣1)x+t﹣2=0中,△=[﹣(t﹣1)]2﹣4×1×(t ﹣2)=t2﹣6t+9=(t﹣3)2≥0,∴对于任意实数t,方程都有实数根;(2)解:设方程的两根分别为m、n,∵方程的两个根互为相反数,∴m+n=t﹣1=0,解得:t=1.∴当t=1时,方程的两个根互为相反数.22.(8分)(•玉林)在一个不透明的袋子中有一个黑球a和两个白球b,c(除颜色外其他均相同).用树状图(或列表法)解答下列问题:(1)小丽第一次从袋子中摸出一个球不放回,第二次又从袋子中摸出一个球.则小丽两次都摸到白球的概率是多少?(2)小强第一次从袋子中摸出一个球,摸到黑球不放回,摸到白球放回;第二次又从袋子中摸出一个球,则小强两次都摸到白球的概率是多少?【解答】解:(1)如图,共6种情况,两次都摸出白球的情况数有2种,所以概率为;(2)共8种情况,第一次摸到白球的可能性为,如果第一次摸到白球,那么第二次又摸到白球的概率是,那么两次摸到白球的概率是×=.23.(9分)(•玉林)如图,AB是⊙O的直径,AC是上半圆的弦,过点C作⊙O的切线DE交AB的延长线于点E,过点A作切线DE的垂线,垂足为D,且与⊙O交于点F,设∠DAC,∠CEA的度数分别是α,β.(1)用含α的代数式表示β,并直接写出α的取值范围;(2)连接OF与AC交于点O′,当点O′是AC的中点时,求α,β的值.【解答】解:(1)连接OC.∵DE是⊙O的切线,∴OC⊥DE,∵AD⊥DE,∴AD∥OC,∴∠DAC=∠ACO,∵OA=OC,∴∠OCA=∠OAC,∴∠DAE=2α,∵∠D=90°,∴∠DAE+∠E=90°,∴2α+β=90°(0°<α<45°).(2)连接OF交AC于O′,连接CF.∵AO′=CO′,∴AC⊥OF,∴FA=FC,∴∠FAC=∠FCA=∠CAO,∴CF∥OA,∵AF∥OC,∴四边形AFCO是平行四边形,∵OA=OC,∴四边形AFCO是菱形,∴AF=AO=OF,∴△AOF是等边三角形,∴∠FAO=2α=60°,∴α=30°,∵2α+β=90°,∴β=30°,∴α=β=30°.24.(9分)(•玉林)某新建成学校举行美化绿化校园活动,九年级计划购买A,B两种花木共100棵绿化操场,其中A花木每棵50元,B花木每棵100元.(1)若购进A,B两种花木刚好用去8000元,则购买了A,B两种花木各多少棵?(2)如果购买B花木的数量不少于A花木的数量,请设计一种购买方案使所需总费用最低,并求出该购买方案所需总费用.【解答】解:(1)设购买A种花木x棵,B种花木y棵,根据题意,得:,解得:,答:购买A种花木40棵,B种花木60棵;(2)设购买A种花木a棵,则购买B种花木(100﹣a)棵,根据题意,得:100﹣a≥a,解得:a≤50,设购买总费用为W,则W=50a+100(100﹣a)=﹣50a+10000,∵W随a的增大而减小,∴当a=50时,W取得最小值,最小值为7500元,答:当购买A种花木50棵、B种花木50棵时,所需总费用最低,最低费用为7500元.25.(10分)(•玉林)如图,在等腰直角三角形ABC中,∠ACB=90°,AC=BC=4,D是AB的中点,E,F分别是AC,BC上的点(点E不与端点A,C重合),且AE=CF,连接EF 并取EF的中点O,连接DO并延长至点G,使GO=OD,连接DE,DF,GE,GF.(1)求证:四边形EDFG是正方形;(2)当点E在什么位置时,四边形EDFG的面积最小?并求四边形EDFG面积的最小值.【解答】(1)证明:连接CD,如图1所示.∵△ABC为等腰直角三角形,∠ACB=90°,D是AB的中点,∴∠A=∠DCF=45°,AD=CD.在△ADE和△CDF中,,∴△ADE≌△CDF(SAS),∴DE=DF,∠ADE=∠CDF.∵∠ADE+∠EDC=90°,∴∠EDC+∠CDF=∠EDF=90°,∴△EDF为等腰直角三角形.∵O为EF的中点,GO=OD,∴GD⊥EF,且GD=2OD=EF,∴四边形EDFG是正方形;(2)解:过点D作DE′⊥AC于E′,如图2所示.∵△ABC为等腰直角三角形,∠ACB=90°,AC=BC=4,∴DE′=BC=2,AB=4,点E′为AC的中点,∴2≤DE<2(点E与点E′重合时取等号).∴4≤S=DE2<8.四边形EDFG∴当点E为线段AC的中点时,四边形EDFG的面积最小,该最小值为4.26.(12分)(•玉林)如图,一次函数y=k1x+5(k1<0)的图象与坐标轴交于A,B两点,与反比例函数y=(k2>0)的图象交于M,N两点,过点M作MC⊥y轴于点C,已知CM=1.(1)求k2﹣k1的值;(2)若=,求反比例函数的解析式;(3)在(2)的条件下,设点P是x轴(除原点O外)上一点,将线段CP绕点P按顺时针或逆时针旋转90°得到线段PQ,当点P滑动时,点Q能否在反比例函数的图象上?如果能,求出所有的点Q的坐标;如果不能,请说明理由.【解答】解:(1)如图1,∵MC⊥y轴于点C,且CM=1,∴M的横坐标为1,当x=1时,y=k1+5,∴M(1,k1+5),∵M在反比例函数的图象上,∴1×(k1+5)=k2,∴k2﹣k1=5;(2)如图1,过N作ND⊥y轴于D,∴CM∥DN,∴△ACM∽△ADN,∴,∵CM=1,∴DN=4,当x=4时,y=4k1+5,∴N(4,4k1+5),∴4(4k1+5)=k2①,由(1)得:k2﹣k1=5,∴k1=k2﹣5②,把②代入①得:4(4k2﹣20+5)=k2,k2=4;∴反比例函数的解析式:y=;(3)当点P滑动时,点Q能在反比例函数的图象上;如图2,CP=PQ,∠CPQ=90°,过Q作QH⊥x轴于H,易得:△COP≌△PHQ,∴CO=PH,OP=QH,由(2)知:反比例函数的解析式:y=;当x=1时,y=4,∴M(1,4),∴OC=PH=4,设P(x,0),∴Q(x+4,x),当点Q落在反比例函数的图象上时,x(x+4)=4,x2+4x+4=8,x=﹣2±,当x=﹣2+2时,x+4=2+2,如图2,Q(2+2,﹣2+2);当x=﹣2﹣2时,x+4=2﹣2,如图3,Q(2﹣2,﹣2﹣2);如图4,CP=PQ,∠CPQ=90°,设P(x,0),过P作GH∥y轴,过C作CG⊥GH,过Q作QH⊥GH,易得:△CPG≌△PQH,∴PG=QH=4,CG=PH=x,∴Q(x﹣4,﹣x),同理得:﹣x(x﹣4)=4,解得:x1=x2=2,∴Q(﹣2,﹣2),综上所述,点Q的坐标为(2+2,﹣2+2)或(2﹣2,﹣2﹣2)或(﹣2,﹣2).。
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2009年崇左市初中毕业升学考试数 学(全卷满分:120分;考试时间:120分钟)一、填空题:本大题共10小题;每小题2分,共20分.请将答案填写在题中的横线上. 1.5-的绝对值是 .2.已知75A ∠=°,则A ∠的余角的度数是 . 3.在函数y =中,自变量x 的取值范围是 .4.分解因式:2242x x -+= .5.写出一个图像位于第一、二、三象限内的一次函数表达式: . 6.一元二次方程230x mx ++=的一个根为1-,则另一个根为 . 7.已知圆锥的侧面积为28πcm ,侧面展开图的圆心角为45°,则该圆锥的母线长为 cm .8.如图,点O 是O ⊙的圆心,点A B C 、、在O ⊙上,A O B C ∥,38A O B ∠=°,则O A C ∠的度数是 .9.当x ≤0时,化简1x --的结果是 .10.如图,正方形A B C D 中,E 是B C 边上一点,以E 为圆心、E C 为半径的半圆与以A 为圆心,A B 为半径的圆弧外切,则sin E A B ∠的值为 .二、选择题:本大题共8小题;每小题3分,共24分.在每小题给出的四个选项中,只有一项是正确的,请将正确答案前的字母填入题后的括号内,每小题选对得3分,选错、不选或多选均得0分.11.如图,直线c 截二平行直线a b 、,则下列式子中一定成立的是( )A .12∠=∠B .13∠=∠C .14∠=∠D .15∠=∠ 12.下列运算正确的是( )A .224236x x x =·B .22231x x -=- C .2222233x x x ÷=D .224235x x x +=13.一个等腰三角形的两边长分别为2和5,则它的周长为( ) A .7 B .9 C .12 D .9或1214.不等式组221x x -⎧⎨-<⎩≤的整数解共有( )A .3个B .4个C .5个D .6个 \OCBA(第8题) D CEB A(第10题) 1 2 3 4 5 a b Pc (第11题)15.如图,下列选项中不是..正六棱柱三视图的是( )A .B .C .D .16.某校九年级学生参加体育测试,一组10人的引体向上成绩如下表: A .9和10 B .9.5和10 C .10和9 D .10和9.517.如图,把矩形A B C D 沿E F 对折后使两部分重合,若150∠=°,则A E F ∠=( )A .110°B .115°C .120°D .130°18.已知点A 的坐标为()a b ,,O 为坐标原点,连结O A ,将线段O A绕点O 按逆时针方向旋转90°得1O A ,则点1A 的坐标为( ) A .()a b -, B .()a b -, C .()b a -, D .()b a -, 三、解答题:本大题共7小题,共76分. 19.(本小题满分6分) 计算:0200912sin 603tan 30(1)3⎛⎫-++- ⎪⎝⎭°°.20.(本小题满分8分) 已知220x -=,求代数式222(1)11x xx x -+-+的值.1 A E D C BF(第17题)21.(本小题满分10分)如图,A B C △中,D E 、分别是边B C A B 、的中点,A D C E 、相交于G .求证:13G E G D C EA D==.22.(本小题满分10分)一只口袋中放着若干只红球和白球,这两种球除了颜色以外没有任何其他区别,袋中的球已经搅匀,蒙上眼睛从口袋中取出一只球,取出红球的概率是14.(1)取出白球的概率是多少?(2)如果袋中的白球有18只,那么袋中的红球有多少只?23.(本小题满分12分)五一期间某校组织七、八年级的同学到某景点郊游,该景点的门票全票票价为15元/人,若为50~99人可以八折购票,100人以上则可六折购票.已知参加郊游的七年级同学少于50人,八年级同学多于50人而少于100人.若七、八年级分别购票,两个年级共计应付门票费1575元,若合在一起购买折扣票,总计应付门票费1080元.问: (1)参加郊游的七、八年级同学的总人数是否超过100人? (2)参加郊游的七、八年级同学各为多少人?BCDGE A(第21题)24.(本小题满分14分)如图,在等腰梯形A B C D 中,已知AD BC ∥,24AB D C AD BC ===,,,延长B C 到E ,使C E A D =.(1)证明:B A D D C E △≌△;(2)如果A C B D ⊥,求等腰梯形A B C D 的高D F 的值.25.(本小题满分16分)在平面直角坐标系中,现将一块等腰直角三角板ABC 放在第二象限,斜靠在两坐标轴上,且点(02)A ,,点(10)C -,,如图所示:抛物线22y ax ax =+-经过点B .(1)求点B 的坐标; (2)求抛物线的解析式;(3)在抛物线上是否还存在点P (点B 除外),使A C P △仍然是以A C 为直角边的等腰直角三角形?若存在,求所有点P2009年崇左市初中毕业升学考试数 学 答 案一、1.5 2.15° 3.3x -≥ 4.22(1)x - 5.1y x =+等6.3- 7.8 8.19° 9.1 10.35DABEF (第24题)(第25题)二、11.B 12.A 13.C 14.C 15A 16.D 17.B 18.C 三、19.原式=231123⨯⨯-··········································································· 4分 =0. ········································································································ 6分20.原式=22(1)(1)(1)1x xx x x -+-++····················································································· 2分=2111x xx x -+++ ······························································································· 4分=211x x x +-+ ··································································································· 5分220x -= ,22x ∴=······································································································· 6分 ∴原式211x x +-=+··························································································· 7分∴原式=1 ········································································································ 8分 21.证明:连结E D , ··························································1分D E 、分别是边B C A B 、的中点,12D E D E A C A C ∴=∥,, ······················································3分AC G D EG ∴△∽△, ························································5分 12G E G D D E G CA G A C ∴===, ···················································7分13G E G D C EA D∴==. ·····································································································10分22.(1)()()P 1P =-取出白球取出红球 ·················································································· 3分 =13144-= ··················································································································· 4分(2)设袋中的红球有x 只,则有 ·················································································· 5分1184x x =+ (或183184x =+)················································································ 8分解得6x =所以,袋中的红球有6只.··························································································10分 23.(1)全票为15元,则八折票价为12分,六折票价为9元.··································· 2分1001515001575⨯=< ····························································································· 4分∴参加郊游的七、八年级同学的总人数必定超过100人. ············································· 5分 (2)设七、八年级参加郊游的同学分别有x 人、y 人 ·················································· 6分 由(1)及已知,5050100100x y x y <<<+>,,. ·················································· 7分 BCDG E A依题意可得:151215759()1080x y x y +=⎧⎨+=⎩······································································································10分 解得4575x y =⎧⎨=⎩······················································································································ 11分 答:参加郊游的七、八年级同学分别为45人和75人.················································12分24.(1)证明:A D B C C D A D C E ∴∠=∠ ∥,. ····················································· 1分又 四边形A B C D 是等腰梯形,B A D C D A ∴∠=∠, ················································ 2分 B A D D C E ∴∠=∠. ·································································································· 3分A B D C A D C E == ,,B A D DC E ∴△≌△. ································································································· 5分 (2)AD CE A D B C =∴ ,∥,四边形A C E D 是平行四边形, ·································· 7分 A C D E ∴∥. ············································································································· 8分 A C B D D E B D ⊥∴⊥ ,. ························································································ 9分由(1)可知,B A D D C E △≌△,D E BD ∴=. ····················································10分 所以,B D E △是等腰直角三角形,即45E ∠=°,D F FEF C C E ∴==+. ··························································································12分四边形A B C D 是等腰梯形,而24AD BC ==,, 1F C ∴=. ·················································································································13分 2C E A D ==3D F ∴=. ················································································································14分25.(1)过点B 作BD x ⊥轴,垂足为D ,9090BC D AC O AC O C AO ∠+∠=∠+∠= °,° B C D C A O ∴∠=∠; ················································ 1分又90BDC COA CB AC ∠=∠== °;,BC D C AO ∴△≌△, ··············································· 2分 12B D O C C D O A ∴====, ································· 3分∴点B 的坐标为(31)-,;············································ 4分 (2)抛物线22y ax ax =+-经过点(31)B -,,则得到1932a a =--, ······················· 5分 解得12a =,所以抛物线的解析式为211222y x x =+-; ············································· 7分(3)假设存在点P ,使得A C P △仍然是以A C 为直角边的等腰直角三角形:①若以点C 为直角顶点;则延长B C 至点1P ,使得1P C BC =,得到等腰直角三角形1AC P △, ·························· 8分 过点1P 作1P M x ⊥轴,11190C P BC M C P BC D P M C BD C =∠=∠∠=∠= ,,°;1M P C D BC ∴△≌△···································································································10分 121C M C D P M BD ∴====,,可求得点1P (1,-1); ·········································· 11分 ②若以点A 为直角顶点;则过点A 作2AP C A ⊥,且使得2AP AC =,得到等腰直角三角形2AC P △, ··············12分 过点2P 作2P N y ⊥轴,同理可证2AP N C AO △≌△; ···············································13分 221N P O A AN O C ∴====,,可求得点2(21)P ,;·················································14分 经检验,点1(11)P -,与点2(21)P ,都在抛物线211222y x x =+-上. ····························16分。