钦州市2009年初中毕业升学考试试题卷

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钦州市2009年初中毕业升学考试试题卷数学(考试时间:120分钟;满分:120分)温馨提示:1.请将所有答案写在答题卷上,在试题卷上作答无效.试题卷、答题卷均要上交.2.请你在答题前先将你的准考证号、姓名填写到答题卷的相应位置上.3.可以使用计算器,但未注明精确度的计算问题不得采取近似计算,建议根据题型特点把握好使用计算器的时机.4.只装订答题卷!一、填空题:请将答案填写在答题卷中的横线上,本大题共10小题;每小题2分,共20分.1.分解因式:a2+2a=_▲_.2.如图,在□ABCD中,∠A=120°,则∠D=_▲_°.3.在钦州保税港区的建设中,建设者们发扬愚公移山、精卫填海的精神,每天吹沙填海造地约40亩.据统计,最多一天吹填的土石方达316700方,这个数字用科学计数法表示为_▲_方(保留三个有效数字).4.如图中物体的一个视图(a)的名称为_▲_.5.在不透明的袋子中装有4个红球和7个黄球,每个球除颜色外都相同,从中任意摸出一个球,摸到_▲_球的可能性大.6.钟表分针的运动可看作是一种旋转现象,一只标准时钟的分针匀速旋转,经过15分钟旋转了_▲_度.7.一次函数的图象过点(0,2),且函数y的值随自变量x的增大而增大,请写出一个符合条件的函数解析式:_▲_.8.如图是反比例函数y=kx在第二象限内的图象,若图中的矩形OABC的面积为2,则k=_▲_.9.如图,P A、PB分别与⊙O相切于点A、B,⊙O的切线EF分别交P A、PB于点E、F,切点C在AB上,若PA长为2,则△PEF的周长是_▲_.10.一组按一定规律排列的式子:-2a,52a,-83a,114a,…,(a≠0)则第n个式子是_▲_(n为正整数).从正面看(a)xyABC O∙ABPCEF∙OABCD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答题卷中选择题答题卡对应的空格内.每小题选对得3分,选错,不选或多选均得零分.11.实数1的倒数是()A.0 B.1 C.-1 D.±112.sin30°的值为()A .32B .22C.12D .3313.某校计划修建一座既是中心对称图形又是轴对称图形的花坛,从学生中征集到的设计方案有等腰三角形、正三角形、等腰梯形、菱形等四种方案,你认为符合条件的是()A.等腰三角形B.正三角形C.等腰梯形 D.菱形14.点P(-2,1)关于y轴对称的点的坐标为()A.(-2,-1)B.(2,1)C.(2,-1) D.(-2,1)15.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16.将抛物线y=2x2向上平移3个单位得到的抛物线的解析式是()A.y=2x2+3 B.y=2x2-3C.y=2(x+3)2D.y=2(x-3)217.如图,AC=AD,BC=BD,则有()A.AB垂直平分CD B.CD垂直平分ABC.AB与CD互相垂直平分D.CD平分∠ACB18.如图,有一长为4cm,宽为3cm的长方形木板在桌面上做无滑动的翻滚(顺时针方向),木板上的顶点A的位置变化为A→A1→A2,其中第二次翻滚被桌面上一小木块挡住,使木板边沿A2C与桌面成30°角,则点A翻滚到A2位置时,共走过的路径长为()A.10cm B.3.5πcmC.4.5πcm D.2.5πcm三、解答题:本大题8题,共76分.解答应写出文字说明或演算步骤.19.(本题满分10分,每小题5分)(1)解不等式:13x-1<0,并把它的解集在数轴上表示出来;(2)解方程:21x+=1.20.(本题满分10分,每小题5分)(1)当0b≠时,比较1+b与1的大小;(2)先化简,再求值:311a aa a⎛⎫-⎪++⎝⎭·21aa-,其中a=7+1(精确到0.01).A BCDAB CDOA1A2AB C21.(本题满分10分,每小题5分)(1)已知:如图1,在矩形ABCD 中,AF =BE .求证:DE =CF ; (2)已知:如图2,⊙O 1与坐标轴交于A (1,0)、B (5,0)两点,点O 1的纵坐标为5.求⊙O 1的半径.22.(本题满分8分)小王、小李和小林三人准备打乒乓球,他们约定用“抛硬币”的方式来确定哪两个人先上场,三人手中各持有一枚质地均匀的硬币,同时将手中硬币抛落到水平地面为一个回合.落地后,三枚硬币中,恰有两枚正面向上或反面向上的这两枚硬币持有人先上场;若三枚硬币均为正面向上或反面向上,属于不能确定.(1)请你完成下图中表示“抛硬币”一个回合所有可能出现的结果的树状图; (2)求一个回合能确定两人先上场的概率.解:(1)树状图为:23.(本题满分10分) 小王购买了一套经济适用房,他准备将地面铺上地砖,地面结构如图所示.根据图中的数据(单位:m ),解答下列问题: (1)写出用含x 、y 的代数式表示的地面总面积;(2)已知客厅面积比卫生间面积多21m 2,且地面总面积是卫生间面积的15倍,铺1m 2地砖的平均费用为80元,求铺地砖的总费用为多少元?开始正面 正面 反面 正面 反面 正面 反面小王 小李 小林 不确定确定结果 确定确定B A O 图2 x y A B O 1O A DC B 图1 F E63y 22x 客厅 卧室 厨房 卫 生 间24.(本题满分8分)如图是近三年广西生产总值增速(累计,%)的折线统计图,据区统计局初步核算,2009年一季度全区生产总值为1552.38亿元,与去年同一时期相比增长12.9%(如图,折线图中其它数据类同).根据统计图解答下列问题:(1)求2008年一季度全区生产总值是多少(精确到0.01亿元)?(2)能否推算出2007年一季度全区生产总值?若能,请算出结果(精确到0.01亿元). (3)从这张统计图中,你有什么发现?用一句话表达你的看法.25.(本题满分10分)已知:如图,在Rt △ABC 中,∠ABC =90°,以AB 上的点O 为圆心,OB 的长为半径的圆与AB 交于点E ,与AC 切于点D .(1)求证:BC =CD ; (2)求证:∠ADE =∠ABD ;(3)设AD =2,AE =1,求⊙O 直径的长.26.(本题满分10分)如图,已知抛物线y =34x 2+bx +c 与坐标轴交于A 、B 、C 三点, A 点的坐标为(-1,0),过点C 的直线y =34tx -3与x 轴交于点Q ,点P 是线段BC 上的一个动点,过P 作PH ⊥OB 于点H .若PB =5t ,且0<t <1.(1)填空:点C 的坐标是_▲_,b =_▲_,c =_▲_;∙ABCD EO15.112.912.813.113.011.315.015.115.3101214161季度1-2季度1-3季度1-4季度1季度1-2季度1-3季度1-4季度1季度近三年广西生产总值增速(累计,%) 增长率/%数据来源:广西区统计局年份2007年 2008年 2009年(2)求线段QH 的长(用含t 的式子表示);(3)依点P 的变化,是否存在t 的值,使以P 、H 、Q 为顶点的三角形与△COQ 相似?若存在,求出所有t 的值;若不存在,说明理由.附加题:(本题满分10分,每小题5分)请你把上面的解答再认真地检查一遍,别留下什么遗憾,并估算一下成绩是否达到了80分,如果你的全卷得分低于80分,则本题的得分将计入全卷总分,但计入后全卷总分最多不超过80分;如果你全卷得分已经达到或超过80分,则本题的得分不计入全卷总分.(1)计算2 3的结果是_▲_;(2)一组数据1,2,3,它的平均数是_▲_.A B x yO QHP C祝贺你,你真棒!但还是请你再检查一遍!钦州市2009年初中毕业升学考试参考答案及评分标准数学评卷说明:1.填空题和选择题中的每小题,只有满分和零分两个评分档,不给中间分.2.解答题每小题的解答中所对应的分数,是指考生正确解答到该步骤所应得的累计分数.考生的其他解法,请参照评分意见进行评分.3.如果考生在解答的中间过程出现计算错误,但并没有改变试题的实质和难度,其后续部分酌情给分,但最多不超过正确解答分数的一半;若出现严重的逻辑错误,后续部分就不再给分.一、填空题:(每小题2分,共24分)1.a(a+2)2.60 3.3.17×105 4.主视图5.黄6.907.y=kx+2(k>0即可)8.-2 9.4 10.31 (1)nnan--二、选择题:(每小题3分,共24分)题号11 12 13 14 15 16 17 18答案 B C D B B A A B三、解答题:(本大题共8小题,共76分.解答应写出文字说明或演算步骤)19.解:(1)去分母,移项,得x<3.···············································································3分这个不等式的解集在数轴上表示如下:∙30····················································································5分(2)两边都乘以x+1,得2=x+1. ·········································································································7分移项,合并同类项,得x=1.···············································································································8分当x=1时,x+1=2≠0,·············································································9分∴原方程的根是:x=1. ··············································································10分20.解:(1)∵b≠0时,∴b>0或b<0.··········································································1分当b>0时,1+b>1, ····················································································3分当b<0时,1+b<1; ····················································································5分(2)原式=2211a aa a-⨯+·······················································································6分=2(1)(1)1a a aa a+-⨯+············································································7分=2(a-1).····························································································8分∵a=7+1,∴原式=2(a-1)=2(7+1-1) ···············································································9分=27≈5.29. ················································································· 10分21.(1)证明:∵AF =BE ,EF =EF ,∴AE =BF . ··························· 1分∵四边形ABCD 是矩形,∴∠A =∠B =90°,AD =BC . ··································· 3分 ∴△DAE ≌△CBF . ···················································· 4分 ∴DE =CF ; ································································ 5分(2)解:过点O 1作O 1C ⊥AB ,垂足为C ,则有AC =BC . ······························································· 6分 由A (1,0)、B (5,0),得AB =4,∴AC =2. ········ 7分 在1Rt AO C △中,∵O 1的纵坐标为5,∴O 1C =5. ································································· 9分∴⊙O 1的半径O 1A =22221(5)2O C AC +=+=3. ······························ 10分22.解:(1)树状图为:(答对一组得1分); ······················································································· 4分 (2)由(1)中的树状图可知:P (一个回合能确定两人先上场)=68=34. ··············································· 8分 23.解:(1)地面总面积为:(6x +2y +18)m 2; ······························································ 4分(2)由题意,得6221,6218152.x y x y y -=⎧⎨++=⨯⎩ ···························································· 6分解之,得4,3.2x y =⎧⎪⎨=⎪⎩ ····························································································· 8分 ∴地面总面积为:6x +2y +18=6×4+2×32+18=45(m 2). ·················· 9分 ∵铺1m 2地砖的平均费用为80元,∴铺地砖的总费用为:45×80=3600(元). ················································ 10分开始正面 反面 正面反面正面反面正面 反面 正面 反面 正面 反面 正面 反面小王 小李 小林 不确定确定结果 确定确定确定确定确定不确定B AO图2x yA BO 1O CAD CB F E24.解:(1)根据题意,2009年一季度全区生产总值为1552.38亿元,设2008年一季度全区生产总值为x 亿元,则1552.38xx-=12.9%. ··········· 2分 解之,得x ≈1375.00(亿元). ···································································· 3分 答:2008年一季度全区生产总值约是1375.00亿元; ·································· 4分 (2)能推算出2007年一季度全区生产总值. ························································ 5分设2007年一季度全区生产总值为y 亿元,同理,由(1)得1375.00yy-=11.3%. ···················································································· 6分 解之,得y ≈1235.40(亿元).所以2007年一季度全区生产总值约是1235.40亿元; ································· 7分 (3)近三年广西区生产总值均为正增长;2008年1季度增长率较2007年同期增长率有较大幅度下降;2009年1季度增长率较2008年同期增长率有所上升,经济发展有所回暖;2007年广西经济飞速发展;….等等,只要能有自己的观点即可给分. ··································································································· 8分25.解:(1)∵∠ABC =90°,∴OB ⊥BC . ································································ 1分 ∵OB 是⊙O 的半径,∴CB 为⊙O 的切线. ················································· 2分 又∵CD 切⊙O 于点D ,∴BC =CD ; ································································ 3分 (2)∵BE 是⊙O 的直径,∴∠BDE =90°.∴∠ADE +∠CDB =90°.········································ 4分 又∵∠ABC =90°,∴∠ABD +∠CBD =90°. ················································································ 5分 由(1)得BC =CD ,∴∠CDB =∠CBD .∴∠ADE =∠ABD ; ························································································· 6分 (3)由(2)得,∠ADE =∠ABD ,∠A =∠A .∴△ADE ∽△ABD . ························································································· 7分 ∴AD AB =AEAD. ································································································ 8分 ∴21BE+=12,∴BE =3, ·············································································· 9分 ∴所求⊙O 的直径长为3. ·········································································· 10分∙ABCD EO26.解:(1)(0,-3),b =-94,c =-3. ······································································· 3分 (2)由(1),得y =34x 2-94x -3,它与x 轴交于A ,B 两点,得B (4,0).∴OB =4,又∵OC =3,∴BC =5. 由题意,得△BHP ∽△BOC , ∵OC ∶OB ∶BC =3∶4∶5,∴HP ∶HB ∶BP =3∶4∶5,∵PB =5t ,∴HB =4t ,HP =3t .∴OH =OB -HB =4-4t .由y =34tx -3与x 轴交于点Q ,得Q (4t ,0).∴OQ =4t . ·································································································· 4分 ①当H 在Q 、B 之间时, QH =OH -OQ=(4-4t )-4t =4-8t . ······································································ 5分 ②当H 在O 、Q 之间时, QH =OQ -OH=4t -(4-4t )=8t -4. ······································································ 6分 综合①,②得QH =|4-8t |; ····································································· 6分 (3)存在t 的值,使以P 、H 、Q 为顶点的三角形与△COQ 相似. ···················· 7分①当H 在Q 、B 之间时,QH =4-8t ,若△QHP ∽△COQ ,则QH ∶CO =HP ∶OQ ,得483t -=34tt,∴t =732. ···································································································· 7分若△PHQ ∽△COQ ,则PH ∶CO =HQ ∶OQ ,得33t =484tt -,即t 2+2t -1=0.∴t 1=2-1,t 2=-2-1(舍去).······················································ 8分 ②当H 在O 、Q 之间时,QH =8t -4.若△QHP ∽△COQ ,则QH ∶CO =HP ∶OQ ,得843t -=34tt,∴t =2532. ···································································································· 9分若△PHQ ∽△COQ ,则PH ∶CO =HQ ∶OQ ,得33t =844t t -,即t 2-2t +1=0. ∴t 1=t 2=1(舍去). ················································································· 10分综上所述,存在t 的值,t 1=2-1,t 2=732,t 3=2532. ··························· 10分附加题:解:(1)8; ············································································································· 5分 (2)2. ··········································································································· 10分A B x y O Q HP C。