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2008新疆建设兵团中考数学试题及答案(word版).doc

新疆维吾尔自治区 新疆生产建设兵团

2008年初中毕业生学业考试

数 学 试 题 卷

考生须知:

1.本试卷分为试题卷和答题卷两部分.

2.试题卷共4页,满分150分.考试时间120分钟. 3.答题卷共4页,所有答案均写在答题卷上...........,写在试题卷上的无效.........

. 4.答题前,考生应先在答题卷密封区内认真填写准考证号、姓名、考场号、座位号、地(州、市、师)、县(市、区、团场)和学校. 5.答题时可以使用科学计算器..........

一、精心选择(本大题共10题,每题所给四个选项中,只有一个是正确的.每题5分,共50分.)

1.|4-|等于( ) A .2- B .2 C .4- D .4 2.2008年5月12日,四川省汶川县发生了里氏8.0级大地震.新

疆各族群众积极捐款捐物,还紧急烤制了2×104个饱含新疆各族人民深情的特色食品——馕(n áng ),运往灾区.每个馕厚度约为2cm ,若将这批馕摞成一摞,其高度大约相当于( ) A .160层楼房的高度(每层高约2.5m ) B .一棵大树的高度 C .一个足球场的长度 D .2000m 的高度

3.如图,下列推理不正确...的是( )

A .∵A

B ∥CD ∴∠AB

C +∠C =180° B .∵∠1=∠2 ∴A

D ∥BC C .∵AD ∥BC ∴∠3=∠4

D .∵∠A +∠ADC =180° ∴AB ∥CD 4.下列事件属于必然事件的是( ) A .打开电视,正在播放新闻 B .我们班的同学将会有人成为航天员 C .实数a <0,则2a <0 D .新疆的冬天不下雪 5.下列调查方式中,合适的是( )

A .要了解约90万顶救灾帐蓬的质量,采用普查的方式

B .要了解外地游客对旅游景点“新疆民街”的满意程度,采用抽样调查的方式

C .要保证“神舟七号”飞船成功发射,对主要零部件的检查采用抽样调查的方式

D .要了解全疆初中学生的业余爱好,采用普查的方式 6.在函数1y x =

的图象上有三个点的坐标分别为(1,1y )、(12

,2y )、(3-,3y ),函数值y 1、y 2、y 3的大小关系是( )

A .y 1<y 2<y 3

B .y 3<y 2<y 1

C .y 2<y 1<y 3

D .y 3<y 1<y 2

7.如图,ABC △中BC 边上的高为1h ,DEF △中DE 边上的高为2h ,下列结论正确的是( )

A .12h h >

B .12h h <

C .12h h =

D .无法确定

8.傍晚,小明陪妈妈在路灯下散步,当他们经过路灯时,身体的影长( ) A .先由长变短,再由短变长 B .先由短变长,再由长变短

C .保持不变

D .无法确定

9.如图,圆内接四边形ABCD 是由四个全等的等腰梯形组成,AD 是⊙O 的直径,则∠BEC 的度数为( ) A .15° B .30° C .45° D .60°

10.古尔邦节,6位朋友均匀地围坐在圆桌旁共度佳节.圆桌半径为60cm ,每人离圆桌的距离均为10cm ,现又来了两名客人,每人向后挪动了相同的距离,再左右调整位置,使8人都坐下,并且8人之间的距离与原来6人之间的距离(即在圆周上两人之间的圆弧的长)相等.设每人向后挪动的距离为x ,根据题意,可列方程( )

A .

2π(6010)2π(6010)

68x +++=

B .2π(60)2π60

86

x +?=

C .2π(6010)62π(60)8x +?=+?

D .2π(60)82π(60)6x x -?=+?

二、合理填空(本大题共4题,每题5分,共20分)

11.根据下列图形的排列规律,第2008个图形是福娃 (填写福娃名称即可).

12.如图,在平面直角坐标系中,线段11A B 是由线段AB 平移得到的,已知A B ,两点的坐

标分别为(23)A -,

,(31)B -,,若1A 的坐标为(34),,则1B 的坐标为 .

13.已知一元二次方程有一个根是2,那么这个方程可以是 (填上一个符合条件的

方程即可).

14.如图,一束光线从y 轴上点A (0,1)发出,经过x 轴上点C 反射后,经过点B (6,2),则光线从A 点到B 点经过的路线的长度为 .(精确到0.01)

三、准确解答(本大题共10题,共80分)

15.(6分)计算:201

2(π6)4

-÷--.

16(6分)化简分式2211

211

x x x x x -+-++-,并从2-、1-、0、1、2中选一个能使分式有意义

的数代入求值. 17.(6分)城区某中学要从自愿报名的张、王、李、赵4名老师中选派2人下乡支教,请用画树状图(或列表)的方法求出张、王两位老师同时被选中的概率. 18.(8分)如图,⊙O 的半径10cm OC =,直线l ⊥CO ,垂足为H ,交⊙O 于A 、B 两点,16cm AB =,直线l 平移多少厘米时能与⊙O 相切?

(1)请你根据以上数据填写下表:

(2)补全折线统计图.

(3)请你从以下两个不同的方面对这两种水果在去年3月份至8月份的销售情况进行分析:

①根据平均数和方差分析;

②根据折线图上两种水果销售量的趋势分析.

20.(8分)如图,某市区南北走向的北京路与东西走向的喀什路相交于点O处.甲沿着喀什路以4m/s的速度由西向东走,乙沿着北京路以3m/s的速度由南向北走.当乙走到O点以北50m处时,甲恰好到点O处.若两人继续向前行走,求两个人相距85m时各自的位置.

21.(8分)如图,在△ABC中,∠C=2∠B,AD是△ABC的角平分线,∠1=∠B.

求证:AB=AC+CD.

22.(9分)某社区计划购买甲、乙两种树苗共600棵,甲、乙两种树苗单价及成活率见下表:

(1

(2)若希望这批树苗成活率不低于90%,并使购买树苗的费用最低,应如何选购树苗?购买树苗的最低费用为多少?

23.(10分)(1)请用两种不同的方法,用尺规在所给的两个矩形中各作一个不为正方形的菱形,且菱形的四个顶点都在矩形的边上.(保留作图痕迹)

(2)写出你的作法.

24.(10分)某工厂要赶制一批抗震救灾用的大型活动板房.如图,板房一面的形状是由矩形和抛物线的一部分组成,矩形长为12m,抛物线拱高为5.6m.

(1)在如图所示的平面直角坐标系中,求抛物线的表达式.

(2)现需在抛物线AOB的区域内安装几扇窗户,窗户的底边在AB上,每扇窗户宽1.5m,高1.6m,相邻窗户之间的间距均为0.8m,左右两边窗户的窗角所在的点到抛物线的水平距离至少为0.8m.请计算最多可安装几扇这样的窗户?

新疆维吾尔自治区 新疆生产建设兵团

2008年初中毕业生学业考试

数学试卷参考答案及评分标准

(满分150分)

说明:本参考答案供阅卷教师评卷时使用.阅卷中,考生如有其它解法,只要正确、合理,均可得相应分值.

11.欢欢 12.(2,2) 13.2

4x =(答案不惟一) 14.6.71 三、解答题(本大题共10题,共80分)

15.(6分)解:原式11

144

=

÷+ ··············································································· 4分

=······························································································· 6分 16.(6分)解:原式2

(1)(1)1

(1)1

x x x x x -++=

-+- ······································································· 1分 11

11

x x x x -+=

-+- ························································································································ 2分 22

(1)(1)(1)(1)

x x x x --+=

-+ ··············································································································· 3分 241x

x -=

- ·································································································································· 5分 把0x =代入 原式0= ·································································································································· 6分 或把2x =代入

原式2428

213-?==-- ················································································································ 6分 或把2x =-代入 原式2

4(2)8

(2)13

-?-=

=--. ················································ 6分17.(6分)解:方法1:画树状图

·············································································· 4分

张、王两位老师同时被选中的概率是16

. ············································································ 6分 方法2:列表

张、王两位老师同时被选中的概率是

1

6

. ············································································ 6分

18.(8分)解法1:如图,连结OA ,延长CO 交⊙O 于D , ∵l ⊥OC ,

∴OC 平分AB . ∴AH =8. ······················································································ 3分

在Rt △AHO 中,6OH , ·

······ 6分 ∴4cm 16cm CH DH ==,.

答:直线AB 向左移4cm ,或向右平移16cm 时与圆相切. ················································ 8分 解法2:设直线AB 平移cm x 时能与圆相切,

222(10)810x -+=

················································································································ 3分 116x =

24x =

∴4cm 16cm CH DH ==,. ····························································································· 8分

答:略.

(只答一个方向的平移扣2分) 19.(9分) 解:(1)

(2)

·························································· (7分)

(3)①由于平均数相同,22

S S <大枣葡萄

,所以大枣的销售情况相对比较稳定. ················ 8分 ②从图上看,葡萄的月销售量呈上升趋势. ········································································· 9分 (答案不惟一,合理均可得分) 20.(8分)解法1:设经过x 秒时两人相距85m ································································· 1分 根据题意得:222(4)(503)85x x ++= ················································································ 4分 化简得:2

121890x x +-=

解得:12921x x ==-,(不符合实际情况,舍去) ·························································· 6分

当9x =时,43650377x x =+=,

∴当两人相距85m 时,甲在O 点以东36m 处,乙在O 点以北77m 处. ·························· 8分 解法2:设甲与O 处的距离为x m 时,两人相距85m

则乙与O 处的距离为350m 4x ??

+

???

·

······················································································ 1分 2

2

2350854x x ??

++= ???

·

········································································································· 4分 解得:123684x x ==-,(不符合实际情况,舍去 ) ······················································ 6分 当33650774

x x =+=, ········································································································· 7分 答:当两人相距85米时,甲在O 点以东36米处,乙在O 点以北77米处. ···················· 8分 21.(8分)证明: ∵∠1=∠B

∴∠AED =2∠B ,DE =BE ········································································································ 2分 ∴∠C =∠AED ························································································································· 3分 在△ACD 和△AED 中

CAD EAD AD AD

C AE

D ∠=∠??

=??∠=∠?

∴△ACD ≌△AED ··················································································································· 5分

∴AC =AE ,CD =DE ,∴CD =BE . ·························································································· 6分 ∴AB =AE +EB =AC +CD . ········································································································· 8分 22.(9分)解:(1)设最多可购买乙树苗x 棵,则购买甲树苗(600 x -)棵 ················ 1分

60(600)8044000x x -+≤ ································································································· 3分 400x ≤.

答:最多可购买乙树苗400棵. ···························································································· 5分 (2)设购买树苗的费用为y 则60(600)80y x x =-+

2036000y x =+ ················································································································ 6分

根据题意 0.88(600)0.960.9600x x -+?≥

150x ≥

∴当150x =时,y 取最小值. ······························································································ 8分

min 2015036000y =?+

39000=.

答:当购买乙树苗150棵时费用最低,最低费用为39000元. ·········································· 9分 (本题不答不扣分) 23.(10分)解:(1)所作菱形如图①、②所示.

说明:作法相同的图形视为同一种.例如类似图③、图④的图形视为与图②是同一种.

(作出一个图形得3分) (2)图①的作法:

作矩形A 1B 1C 1D 1四条边的中点E 1、F 1、G 1、H 1; 连接H 1E 1、E 1F 1、G 1F 1、G 1H 1. 四边形E 1F 1G 1H 1即为菱形. 图②的作法:

在B 2C 2上取一点E 2,使E 2C 2>A 2E 2且E 2不与B 2重合; 以A 2为圆心,A 2E 2为半径画弧,交A 2D 2于H 2;

以E 2为圆心,A 2E 2为半径画弧,交B 2C 2于F 2; 连接H 2F 2,则四边形A 2E 2F 2H 2为菱形. (写对一个作法得2分)

(此题答案不惟一,只要画法及作法合理、正确,均可酌情得分.)

24.(10分)解:(1)设抛物线的表达式为2y ax = ····· 1分

点(6 5.6)B -,

在抛物线的图象上. ∴ 5.636a -=

7

45

a =-

·········································································· 3分 ∴抛物线的表达式为2

745y x =- ·························································································· 4分 (2)设窗户上边所在直线交抛物线于C 、D 两点,D 点坐标为(k ,t )

已知窗户高1.6m ,∴ 5.6( 1.6)4t =---=- ······································································· 5分

2

7445

k --=

125.07 5.07k k -≈,≈(舍去) ·

························································································ 6分 ∴ 5.07210.14CD =?≈(m ) ···························································································· 7分

又设最多可安装n 扇窗户

∴1.50.8(1)10.14n n ++≤ ··································································································· 9分

4.06n ≤.

答:最多可安装4扇窗户. ································································································· 10分 (本题不要求学生画出4个表示窗户的小矩形)

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