数学试卷
考生注意:
1.本卷含四大题,共25题;
2.除第一、二大题外,其余各题如无特别说明,都必须写出证明或计算的主要步骤. 一、填空题:(本大题共12题,满分36分)[只要求直接写出结果,每个空格填对得3分,否则得零分]
1.计算:(3)2 .
2.分解因式:2a2ab .
211 . xx134.已知函数f(x),则f(1) .
x23.化简:5.函数y2x2的定义域是 .
6.若方程x2x10的两个实数根为x1,x2,则x1x2 . 7.方程1x2的根是 .
8.如图1,正比例函数图象经过点A,该函数解析式是 .
y
A A 3 D F
B O 1 x E C
图2
图1
9.如图2,E为平行四边形ABCD的边BC延长线上一点,连结AE,交边CD于点F.在不添加辅助线的情况下,请写出图中一对相似三角形: .
10.如果两个圆的一条外公切线长等于5,另一条外公切线长等于2a3,那么a . 11.如图3,在直角坐标平面内,线段AB垂直于y轴,垂足为B,且AB2,如果将线段AB沿y轴翻折,点A落在点C处,那么点C的横坐标是 .
y B A O 图3
x 图4
12.图4是44正方形网格,请在其中选取一个白色的单位正方形并涂黑,使图4中黑色部分是一个中心对称图形. 二、选择题:(本大题共4题,满分16分)
【下列各题的四个结论中,有且只有一个结论是正确的,把正确结论的代号写在题后的圆括号内,选对得4分;不选、错选或者多选得零分】 13.在下列二次根式中,与a是同类二次根式的是( ) A.2a
B.3a2
C.a3
D.a4 14.如果一次函数ykxb的图象经过第一象限,且与y轴负半轴相交,那么( ) A.k0,b0
B.k0,b0
C.k0,b0
D.k0,b0
15.已知四边形ABCD中,∠A∠B∠C90,如果添加一个条件,即可推出该四边形是正方形,那么这个条件可以是( ) A.∠D90
B.ABCD
C.ADBC
D.BCCD
16.小明不慎把家里的圆形玻璃打碎了,其中四块碎片如图5所示,为配到与原来大小一样的圆形玻璃,小明带到商店去的一块玻璃碎片应该是( ) A.第①块 B.第②块 C.第③块 D.第④块 三、(本大题共5题,满分48分) 17.(本题满分9分) 图5
3x0,解不等式组:4x3x并把解集在数轴上表示出来.
,6325 4 3 2 1 0 1 2 3 4 5
18.(本题满分9分)
x23x2x10. 解方程:2x1x1
19.(本题满分10分,第(1)小题满分6分,第(2)小题满分4分)
0),如图6,在直角坐标平面内,O为原点,点A的坐标为(10,点B在第一象限内,BO5,sin∠BOA3. 5y B 求:(1)点B的坐标;(2)cos∠BAO的值. x O 20.(本题满分10分,第(1)小题满分4分,第(2),(3)小题满分各3分)
图6
初三学生小丽、小杰为了解本校初二学生每周上网的时间,各自在本校进行了抽样调查.小丽调查了初二电脑爱好者中40名学生每周上网的时间,算得这些学生平均每周上网时间为2.5小时;小杰从全体初二学生名单中随机抽取了40名学生,调查了他们每周上网的时间,算得这些学生平均每周上网时间为1.2小时.小丽与小杰整理各自样数据,如表一所示.请根据上述信息,回答下列问题:
(1)你认为哪位学生抽取的样本具有代表性?答: ; 估计该校全体初二学生平均每周上网时间为 小时;
(2)根据具体代表性的样本,把图7中的频数分布直方图补画完整; (3)在具有代表性的样本中,中位数所在的时间段是 小时/周.
人数 22 时间段 小丽抽样 小杰抽样 20 (小时/周) 人数 人数 18 16 6 22 0~1 14 10 10 1~2 12 16 6 2~3 10 8 8 2 3~4 6 (每组可含最低值,不含最高值) 4 表一 2 0 1 2 3 4 小时/周 (每组可含最低值,不含最高值) 图7 21.(本题满分10分)
2001年以来,我国曾五次实施药品降价,累计降价的总金额为269亿元,五次药品降价的年份与相应降价金额如表二所示,表中缺失了2003年、2007年相关数据.已知2007年药品降价金额是2003年药品降价金额的6倍,结合表中信息,求2003年和2007年的药品降价金额. 年份 降价金额(亿元) 2001 54 2003 表二
四、(本大题共4题,满分50分) 22.(本题满分12分,每小题满分各6分)
2004 35 2005 40 2007 ,4),且过点B(3,0). 在直角坐标平面内,二次函数图象的顶点为A(1(1)求该二次函数的解析式;
(2)将该二次函数图象向右平移几个单位,可使平移后所得图象经过坐标原点?并直接写出平移后所得图象与x轴的另一个交点的坐标.
23.(本题满分12分,每小题满分各6分)
如图8,在梯形ABCD中,AD∥BC,CA平分∠BCD,DE∥AC,交BC的延长线于点E,∠B2∠E. (1)求证:ABDC; D A (2)若tgB2,AB5,求边BC的长. 24.(本题满分12分,每小题满分各4分) 如图9,在直角坐标平面内,函数yB 图8
C E
m(x0,m是常数)的图象经过A(1,4),B(a,b),x其中a1.过点A作x轴垂线,垂足为C,过点B作y轴垂线,垂足为D,连结AD,DC,
CB.
(1)若△ABD的面积为4,求点B的坐标; (2)求证:DC∥AB;
(3)当ADBC时,求直线AB的函数解析式. A
B D
O C x 图9 25.(本题满分14分,第(1)小题满分4分,第(2),(3)小题满分各5分)
已知:∠MAN60,点B在射线AM上,AB4(如图10).P为直线AN上一动点,以BP为边作等边三角形BPQ(点B,P,Q按顺时针排列),O是△BPQ的外心. (1)当点P在射线AN上运动时,求证:点O在∠MAN的平分线上;
Px,(2)当点P在射线AN上运动(点P与点A不重合)时,AO与BP交于点C,设Ay ACAOy,求y关于x的函数解析式,并写出函数的定义域;
(3)若点D在射线AN上,AD2,圆I为△ABD的内切圆.当△BPQ的边BP或BQ与圆I相切时,请直接写出点A与点O的距离.
A
P
B B O
Q N M M
图10
A P O Q 备用图
N
2007年上海市初中毕业生统一学业考试
数学试卷答案要点与评分标准
说明:
1.解答只列出试题的一种或几种解法.如果考生的解法与所列解法不同,可参照解答中评分标准相应评分.
2.第一大题只要求直接写出结果,每个空格填对得3分,否则得零分;第二大题每题选对得4分,不选、错选或者多选得零分;17题至25题中右端所注的分数,表示考生正确做对这一步应得分数,评分时,给分或扣分均以1分为单位. 答案要点与评分标准
一、填空题(本大题共12题,满分36分) 1.3 2.2a(ab) 3.
1 4.1 5.x≥2 6.2 7.x3
x(x1)8.y3x 9.△AFD∽△EFC(或△EFC∽△EAB,或△EAB∽△AFD) 10.1 11.2 12.答案见图1
图1
二、选择题(本大题共4题,满分16分) 13. C 14.B 15.D 16.B 三、(本大题共5题,满分48分) 17.解:由3x0,解得x3. ··································································· 3分
4x3x,解得x1. ······································································· 3分 326····································································· 1分 不等式组的解集是1x3. ·
由
解集在数轴上表示正确. ················································································· 2分 18.解:去分母,得x3x(2x1)(x1)0, ··············································· 3分 整理,得3x2x10, ·············································································· 2分 解方程,得x11,x2. ·········································································· 2分
221311是原方程的根,原方程的根是x. ·············· 2分 3319.解:(1)如图2,作BHOA,垂足为H, ················································· 1分
3在Rt△OHB中,BO5,sinBOA,
5BH3. ·································································································· 2分
经检验,x11是增根,x2OH4.……………………………… 1分
3).……………………2分 点B的坐标为(4,(2)OA10,OH4,AH6.………………1分 在Rt△AHB中,BH3,AB35.………… 1分
y B O H 图2 A x
cosBAOAH25.………………………………2分 AB520.(1)小杰;1.2. ·············································································· 2分,2分
(2)直方图正确. ························································································· 3分 (3)0~1. ··································································································· 3分 21.解:[解法一]设2003年和2007年的药品降价金额分别为x亿元、y亿元. ·········· 1分 根据题意,得y6x ………………………………………………………………2分
54x3540y269 ………………………………………………2分 解方程组,得x20 ………………………………………………………………………2分
y120 ………………………………………………………………………2分 答:2003年和2007年的药品降价金额分别为20亿元和120亿元. ·························· 1分 [解法二]设2003年的药品降价金额为x亿元, ······················································ 1分 则2007年的药品降价金额为6x亿元. ······························································· 2分 根据题意,得54x35406x269. ························································ 2分 解方程,得x20,6x120. ···································································· 4分 答:2003年和2007年的药品降价金额分别为20亿元和120亿元. ·························· 1分 四、(本大题共4题,满分50分) 22.解:(1)设二次函数解析式为ya(x1)4, ··········································· 2分
20),04a4,得a1. ········································· 3分 二次函数图象过点B(3,··································· 1分 二次函数解析式为y(x1)24,即yx22x3. ·
(2)令y0,得x2x30,解方程,得x13,x21. ·························· 2分
20)和(1,0). 二次函数图象与x轴的两个交点坐标分别为(3,············································ 2分 二次函数图象向右平移1个单位后经过坐标原点. ·
0). ·平移后所得图象与x轴的另一个交点坐标为(4,·············································· 2分
23.(1)证明:DE∥AC, BCAE. ·························································································· 1分 CA平分BCD, BCD2BCA, ···················································································· 1分 BCD2E, ························································································ 1分
又B2E, BBCD. ·························································································· 1分
························································ 2分 梯形ABCD是等腰梯形,即ABDC. ·
(2)解:如图3,作AFBC,DGBC, 垂足分别为F,G,则AF∥DG.
在Rt△AFB中,tgB2,AF2BF.…………1分 又AB5,且ABAFBF,
222A D 54BFBF,得BF1.……………………1分
同理可知,在Rt△DGC中,CG1.……………1分 AD∥BC,DACACB.
又ACBACD,DACACD,ADDC.
22B F
G C 图3
E
···································································· 1分 DCAB5,AD5.
AD∥BC,AF∥DG,四边形AFGD是平行四边形,FGAD5. ···· 1分
·································································· 1分 BCBFFGGC25.·24.(1)解:函数ym(x0,m是常数)图象经过A(1,4),m4. ··········· 1分 x设BD,AC交于点E,据题意,可得B点的坐标为a,,D点的坐标为0,,
4a4a
4E点的坐标为1,, ···················································································· 1分
aa1,DBa,AE4由△ABD的面积为4,即
4. a14······················································ 1分 a44, ·
2a43得a3,点B的坐标为3,. ··································································· 1分
,0),DE1, (2)证明:据题意,点C的坐标为(1a1,易得EC4,BEa1, a44BEa1AEaa1. ·a1,···················································· 2分 4DE1CEaBEAE. ······························································································ 1分 DECEDC∥AB. ······························································································ 1分 (3)解:DC∥AB,当ADBC时,有两种情况: ①当AD∥BC时,四边形ADCB是平行四边形,
BEAEa1,a11,得a2. 由(2)得,
DECE. ··············································································· 1分 点B的坐标是(2,2)设直线AB的函数解析式为ykxb,把点A,B的坐标代入,
得4kb,k2,解得
b6.22kb·························································· 1分 直线AB的函数解析式是y2x6. ·
②当AD与BC所在直线不平行时,四边形ADCB是等腰梯形,
则BDAC,a4,点B的坐标是(4,1). ············································· 1分 设直线AB的函数解析式为ykxb,把点A,B的坐标代入,
4kb,k1,得解得
14kb.b5···························································· 1分 直线AB的函数解析式是yx5. ·
综上所述,所求直线AB的函数解析式是y2x6或yx5. 25.(1)证明:如图4,连结OB,OP,
O是等边三角形BPQ的外心,OBOP, ··················································· 1分
360120. 圆心角BOP3当OB不垂直于AM时,作OHAM,OTAN,垂足分别为H,T. 由HOTAAHOATO360,且A60,
AHOATO90,HOT120.
BOHPOT. ····················································································· 1分 Rt△BOH≌Rt△POT. ··········································································· 1分 OHOT.点O在MAN的平分线上. ···················································· 1分
当OBAM时,APO360ABOPOBA90.
即OPAN,点O在MAN的平分线上.
综上所述,当点P在射线AN上运动时,点O在MAN的平分线上.
A A P T H B C B P O O Q M
图4
(2)解:如图5,
N
Q M
图5
N
AO平分MAN,且MAN60,
BAOPAO30. ·············································································· 1分
由(1)知,OBOP,BOP120,
CBO30,CBOPAC.
BCOPCA,AOBAPC. ························································· 1分 △ABO∽△ACP. ABAO.ACAOABAP.y4x. ·············································· 1分 ACAP定义域为:x0.························································································· 1分
(3)解:①如图6,当BP与圆I相切时,AO23; ······································· 2分 ②如图7,当BP与圆I相切时,AO43; ··················································· 1分 3③如图8,当BQ与圆I相切时,AO0. ························································ 2分
A P(A) I B D (D) I P B P O O Q N
B Q M
图6
(A) O D I N 图8
Q
N
M
图7
M
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