2007 年上海虹口中考数学真题及答案
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
ab
.
3.化简:
2.分解因式: 22
a
1
x
( )
f x
4.已知函数
1
x
1
3
x
2
.
,则 (1)
f
.
5.函数
y
x
的定义域是
2
.
6.若方程 2 2
x
x
1 0
的两个实数根为 1x , 2x ,则 1
x
x
2
.
x 的根是
7.方程 1
8.如图 1,正比例函数图象经过点 A ,该函数解析式是
.
2
y
.
3
A
O 1
x
图 1
A
B
图 2
D
F
C
E
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 2
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
AB ,如果将线段 AB 沿 y 轴
3a ,那么 a .
.
2
翻折,点 A 落在点C 处,那么点C 的横坐标是
.
y
B
O
图 3
A
x
12.图 4 是 4 4 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
图 4
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.
23a
C. 3a
D. 4a
14.如果一次函数 y
kx b
的图象经过第一象限,且与 y 轴负半轴相交,那么(
)
A. 0
k , 0
b
B. 0
k , 0b
C. 0
k , 0
b
D. 0
k , 0b
15.已知四边形 ABCD 中,
C
∠ ∠ ∠
A
B
90
,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.
∠
D
90
B. AB CD
C. AD BC
D. BC CD
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
C.第③块
三、(本大题共 5 题,满分 48 分)
17.(本题满分 9 分)
B.第②块
D.第④块
)
解不等式组:
x
3
4
3
x
3
2
0
,
图 5
x
6
并把解集在数轴上表示出来.
,
5
4
3
2
1
0 1 2 3 4 5
18.(本题满分 9 分)
解方程:
2
x
x
3
x
2
1
1
2
x
1
x
0
.
19.(本题满分 10 分,第(1)小题满分 6 分,第(2)小题满分 4 分)
如 图 6 , 在 直 角 坐 标 平 面 内 , O 为 原 点 , 点 A 的 坐 标 为 (10 0), , 点 B 在 第 一 象 限 内 ,
BO ,
5
3
5
∠
BOA
sin
求:(1)点 B 的坐标;(2) cos BAO∠
.
的值.
y
B
O
图 6
x
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)
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
(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;
小时/周.
(3)在具有代表性的样本中,中位数所在的时间段是
小时;
时间段
小丽抽样
小杰抽样
(小时/周)
人数
人数
0~1
1~2
2~3
3~4
6
10
16
8
22
10
6
2
(每组可含最低值,不含最高值)
表一
人数
22
20
18
16
14
12
10
8
6
4
2
1
0
(每组可含最低值,不含最高值)
小时/周
2
3
4
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
2001
2003
降价金额(亿元) 54
2004
35
2005
40
2007
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)
在直角坐标平面内,二次函数图象的顶点为 (1
A , ,且过点 (3 0)
B , .
4)
(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.
2B
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∠
∠
(1)求证: AB DC
(2)若 tg
AB ,求边 BC 的长.
2B ,
∠ .
E
;
5
A
, DE
AC∥ ,交 BC 的延长线于点 E ,
D
24.(本题满分 12 分,每小题满分各 4 分)
B
C
E
图 8
如图 9,在直角坐标平面内,函数
my
( 0
x
x ,m 是常数)的图象经过 (1 4)
A , , (
B a b, ,其中 1a .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△
(2)求证: DC
(3)当 AD BC 时,求直线 AB 的函数解析式.
的面积为 4,求点 B 的坐标;
AB∥ ;
y
A
B
D
CO
图 9
x
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:
∠
MAN
60
,点 B 在射线 AM 上,
AB (如图 10). P 为直线 AN 上一动点,以 BP 为边作
4
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∠
(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 AP x ,AC AO y
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,
AD ,圆 I 为 ABD△
的内切圆.当 BPQ△
的边 BP 或 BQ 与圆 I 相切
的平分线上;
2
,
时,请直接写出点 A 与点 O 的距离.
A
O
P
B
A
O
P
B
M
Q
N
M
Q
N
图 10
备用图
参考答案
一、填空题(本大题共 12 题,满分 36 分)
1.3
2. 2 (
a a b
)
3.
1
(
x x
1)
4.1
5.
x ≥
2
6.2
7.
x
3
8. 3
x
y
9. AFD
△
∽△
EFC
(或 EFC
△
∽△
EAB
,或 EAB
△
∽△
AFD
)
10.1
11. 2
12.答案见图 1
图 1
14.B
二、选择题(本大题共 4 题,满分 16 分)
16.B
13. C
三、(本大题共 5 题,满分 48 分)
17.解:由3
15.D
0
由
,解得
4
x
3
3
2
x ,解得 3x .···································································· 3 分
x
x .········································································ 3 分
6
不等式组的解集是 1
.······································································· 1 分
解集在数轴上表示正确.·················································································· 2 分
1
3x
18.解:去分母,得 2 3
x
x
(2
x
1)(
x
1) 0
,················································ 3 分
整理,得 23
x
2
x
1 0
,··············································································· 2 分
.··········································································· 2 分
x
解方程,得 1
x
2
1
,
1
3
x 是原方程的根,原方程的根是
x 是增根, 2
经检验, 1 1
19.解:(1)如图 2,作 BH OA ,垂足为 H ,················································· 1 分
在 Rt OHB△
x .·············· 2 分
BOA
,
BO
sin
中,
,
5
1
3
1
3
3
5
3
4
BH
.···································································································2 分
OH
.……………………………… 1 分
点 B 的坐标为 (4 3), .……………………2 分
y
B
(2)
在 Rt AHB△
OA ,
10
OH ,
4
AH
.………………1 分
6
中,
BH
3
,
AB
3 5
.………… 1 分
x
A
O
H
图 2
cos
BAO
AH
AB
2 5
5
.………………………………2 分
20.(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
y
54
6
x
x
35 40
y
269
……………………………………………………………… 分
……………………………………………… 分
解方程组,得
x
y
20
120
……………………………………………………………………… 分
……………………………………………………………………… 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
2
2
2
2
[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 54
x
.························································· 2 分
解方程,得 20
.····································································· 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)
35 40 6
120
x
x , 6
269
x
22.解:(1)设二次函数解析式为
y
(
a x
1)
2
,············································ 2 分
4
二次函数图象过点 (3 0)
B , , 0
4
4a
,得 1a .········································· 3 分
二次函数解析式为
y
(
x
1)
2
,即
4
y
x
2 2
x
.····································· 1 分
3
(2)令 0
y ,得 2 2
x
x
3 0
,解方程,得 1
x , 2
3
x .·························· 2 分
1
二次函数图象与 x 轴的两个交点坐标分别为 (3 0), 和 ( 1 0)
, .
二次函数图象向右平移 1 个单位后经过坐标原点.··············································2 分
平移后所得图象与 x 轴的另一个交点坐标为 (4 0), .··············································· 2 分
E
AC
BCA
∥ ,
.··························································································· 1 分
,····················································································· 1 分
,························································································· 1 分
23.(1)证明: DE
CA 平分 BCD
,
2
BCA
BCD
2
E
BCD
2B
E
,
又
BCD
B
.··························································································· 1 分
梯形 ABCD 是等腰梯形,即 AB DC
.··························································2 分
(2)解:如图 3,作 AF
垂足分别为 F G, ,则 AF DG∥ .
在 Rt AFB△
BC , DG BC
.…………1 分
2B ,
中, tg
AF
BF
D
,
2
A
又
AB
5
,且 2
AB
2
AF
BF
2
,
2
2
,得
BF
5 4BF
同理可知,在 Rt DGC△
AD BC
∥ , DAC
又 ACB
DC AB
ACD
,
5
1
BF .……………………1 分
CG .……………1 分
ACB
, DAC
中,
1
.
ACD
, AD DC
B
F
C
G
图 3
E
.
AD
.···································································· 1 分
5
∥ , AF DG∥ ,四边形 AFGD 是平行四边形,
AD BC
FG AD
.·····1 分
5
BC BF FG GC
.··································································· 1 分
5
24.(1)解:函数
(
x
, m 是常数)图象经过 (1 4)
A , ,
0
4m .············1 分
2
my
x
设 BD AC, 交于点 E ,据题意,可得 B 点的坐标为
4a
, , D 点的坐标为
a
40
, ,
a
E 点的坐标为
41
, ,····················································································· 1 分
a
1a
, DB a
,
AE
由 ABD△
的面积为 4,即
44
.
a
44
a
1
2
a
4
,························································ 1 分
得 3
a ,点 B 的坐标为
43
, .····································································1 分
3
(2)证明:据题意,点C 的坐标为 (1 0), ,
DE ,
1
1a
,易得
EC
,
4
a
BE a ,
BE
DE
a
1
1
,
a
1
AE
CE
1
44
a
4
a
.······················································ 2 分
a
1
.······························································································· 1 分
BE
AE
DE CE
AB
DC
∥ ,当 AD BC 时,有两种情况:
∥ .······························································································· 1 分
(3)解: DC
①当 AD BC∥ 时,四边形 ADCB 是平行四边形,
AB
由(2)得,
,
1
a ,得 2
a .
1 1
BE
DE CE
AE a
点 B 的坐标是(2,2).················································································ 1 分
设直线 AB 的函数解析式为 y
,把点 A B, 的坐标代入,
kx b
得
4
2
k b
,
2
k b
解得
2
k
,
6.
b
直线 AB 的函数解析式是
y
2
x
.····························································1 分
6
②当 AD 与 BC 所在直线不平行时,四边形 ADCB 是等腰梯形,
则 BD AC
设直线 AB 的函数解析式为 y
,把点 A B, 的坐标代入,
kx b
,
4
a ,点 B 的坐标是(4,1).·············································· 1 分
得
4
1 4
k b
,
.
k b
解得
1
,
k
5
b
直线 AB 的函数解析式是
y
x .····························································· 1 分
5
综上所述,所求直线 AB 的函数解析式是
y
2
x
或
6
y
x .
5
25.(1)证明:如图 4,连结OB OP, ,
O 是等边三角形 BPQ 的外心, OB OP
,··················································· 1 分
圆心角
BOP
360
3
120
.
当OB 不垂直于 AM 时,作OH AM
,OT
AN
,垂足分别为 H T, .
由
HOT
A
AHO
ATO
360
,且
A
60
,
,
HOT
AHO
BOH
ATO
Rt
BOH
△
.点O 在 MAN
OH OT
90
.······················································································1 分
POT
.············································································ 1 分
的平分线上.····················································· 1 分
POT
Rt
≌ △
120
.
时,
APO
当OB AM
即OP
AN
综上所述,当点 P 在射线 AN 上运动时,点 O 在 MAN
360
,点O 在 MAN
的平分线上.
BOP
OBA
A
90
.
的平分线上.
A
O
P
T
Q
图 4
H
B
M
(2)解:如图 5,
B
A
C
O
图 5
P
Q
N
N
M
AO
平分 MAN
,且
MAN
60
,
BAO
PAO
30
.··············································································· 1 分
由(1)知,OB OP
,
BOP
120
,
△
CBO
BCO
ABO
AB
AC
30
∽△
AO
AP
, CBO
PCA
, AOB
ACP
.
.
PAC
APC
.··························································1 分
. AC AO AB AP
.
.···············································1 分
4
x
y
定义域为: 0
x .··························································································1 分
(3)解:①如图 6,当 BP 与圆 I 相切时,
4 3
3
②如图 7,当 BP 与圆 I 相切时,
AO
AO
2 3
;········································2 分
;···················································· 1 分