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)