2008 年福建省厦门市中考数学真题及答案
(试卷满分:150 分
考试时间:120 分钟)
考生注意:本学科考试有两张试卷,分别是本试题(共 4 页 26 题)和答题卡.试题答案要填在答题卡相
应的答题栏内,否则不能得分.
一、选择题(本大题有 7 题,每小题 3 分,共 21 分.每小题有四个选 项,其中有且只有一个选项正确)
1.下面几个数中,属于正数的是(
)
A.3
B.
1
2
C. 2
D. 0
2.由四个相同的小正方体堆成的物体如图所示,它的俯视图是(
)
A.
B.
C.
D.
3.某鞋店试销一种新款女鞋,销售情况如下表所示:
正面
(第 2 题)
型号
数量(双)
22
3
22.5
5
23
10
23.5
15
24
8
24.5
3
25
2
鞋店经理最关心的是,哪种型号的鞋销量最大.对他来说,下列统计量中最重要的是(
A.平均数
C.中位数
B.众数
D.方差
)
4.已知方程|
|x
2 ,那么方程的解是(
)
A. 2
x
B.
x
2
x
C. 1
2
,
x
2
2
D. 4
x
5.下列函数中,自变量 x 的取值范围是 2
x 的函数是(
)
A.
y
x
2
B.
y
1
x
2
C.
y
2
x
1
D.
y
1
x
2
1
6.在平行四边形 ABCD 中,
B
60
,那么下列各式中,不能..成立的是(
)
A.
D
60
B.
A
120
C.
D
C
180
D.
C
A
180
7.在四川抗震救灾中,某抢险地段需实行爆破.操作人员点燃导火线后,要在炸药爆炸前跑到 400 米以
外的安全区域.已知导火线的燃烧速度是 1.2 厘米/秒,操作人员跑步的速度是 5 米/秒.为了保证操作人
员的安全,导火线的长度要超过(
A.66 厘米
B.76 厘米
C.86 厘米
D.96 厘米
)
二、填空题(本大题有 10 小题,每小题 4 分,共 40 分)
8.2008 年北京奥运圣火在厦门的传递路线长是 17400 米,用科学记数法表示为
9.一盒铅笔 12 支, n 盒铅笔共有
10.一组数据:3,5,9,12,6 的极差是
支.
.
米.
11.计算: 3
2
.
12.不等式组
x
4
2
3 0
x
的解集是
.
14.如图,在矩形空地上铺 4 块扇形草地.若扇形的半径均为 r 米,圆心角均为90 ,
(第 14 题)
则铺上的草地共有
15.若 O 的半径为 5 厘米,圆心O 到弦 AB 的距离为 3 厘米,则弦长 AB 为
16 . 如 图 , 在 四 边 形 ABCD 中 , P 是 对 角 线 BD 的 中 点 , E F, 分 别 是 AB CD, 的 中 点 ,
平方米.
厘米.
AD BC
,
PEF
18
,则 PFE
的度数是
CF
D
P
B
A
E
(第 16 题)
.
C
G
D
B
A
E
(第 17 题)
17.如图,点G 是 ABC△
的重心,CG 的延长线交 AB 于 D ,
GA
5cm
,
GC
4cm
,
GB
3cm
,
将 ADG△
绕点 D 旋转180 得到 BDE△
,则 DE
cm, ABC△
的面积
cm2.
三、解答题(本大题有 9 小题,共 89 分)
18.(本题满分 7 分)
先化简,再求值
x
1
x
2
2
x
2
x
x
,其中 2
x .
19.(本题满分 8 分)
四张大小、质地均相同的卡片上分别标有 1,2,3,4.现将标有数字的一面朝下扣在桌子上,然后由小明
从中随机抽取一张(不放回),再从剩下的 3 张中随机取第二张.
(1)用画树状图的方法,列出小明前后两次取得的卡片上所标数字的所有可能情况;
(2)求取得的两张卡片上的数字之积为奇数的概率.
20.(本题满分 9 分)
如图,为了测量电线杆的高度 AB ,在离电线杆 25 米的 D 处,用高 1.20 米的测角仪CD 测得电线杆顶端
A 的仰角
22
,求电线杆 AB 的高.(精确到 0.1 米)
参考数据:sin 22
0.3746
, cos 22
0.9272
, tan 22
0.4040
, cot 22
2.4751
.
A
E
B
C
D
(第 20 题)
21.(本题满分 9 分)
某商店购进一种商品,单价 30 元.试销中发现这种商品每天的销售量 p (件)与每件的销售价 x (元)
满足关系: 100 2
.若商店每天销售这种商品要获得 200 元的利润,那么每件商品的售价应定为多
p
x
少元?每天要售出这种商品多少件?
22.(本题满分 10 分)
已知一次函数与反比例函数的图象交于点 ( 2 1)
P , 和 (1
Q
m, .
)
(1)求反比例函数的关系式;
(2)求Q 点的坐标;
(3)在同一直角坐标系中画出这两个函数图象的示意图,并观察图象回答:当 x 为何值时,一次函数的
值大于反比例函数的值?
23.(本题满分 10 分)
已知:如图, ABC△
(1)求证: PD 是 O 的切线;
2
(2)若
CAB
120
AB
,
中, AB AC
,求 BC 的值.
,以 AB 为直径的 O 交 BC 于点 P , PD AC
于点 D .
C
P
D
A
B
O
(第 23 题)
24.(本题满分 12 分)
2
x
c
y
1)
(
b
已知:抛物线
经过点 ( 1
x
(1)求b c 的值;
(2)若 3b ,求这条抛物线的顶点坐标;
(3)若 3b ,过点 P 作直线 PA y 轴,交 y 轴于点 A ,交抛物线于另一点 B ,且
, .
2 )
b
P
抛物线所对应的二次函数关系式.(提示:请画示意图思考)
BP
2
PA
,求这条
25.(本题满分 12 分)
已知:如图所示的一张矩形纸片 ABCD ( AD AB ),将纸片折叠一次,使点 A 与C 重合,再展开,折
痕 EF 交 AD 边于 E ,交 BC 边于 F ,分别连结 AF 和CE .
(1)求证:四边形 AFCE 是菱形;
(2)若
AE
10cm
, ABF△
的面积为
24cm ,求 ABF△
2
的周长;
(3)在线段 AC 上是否存在一点 P ,使得
若存在,请说明点 P 的位置,并予以证明;若不存在,请说明理由.
AC AP
?
2AE
2
A
B
E
D
C
F
(第 25 题)
26.(本题满分 12 分)
如图,在直角梯形 OABD 中, DB OA∥ ,
OAB
90
,点O 为坐标原点,点 A 在 x 轴的正半轴上,
2
,
AB
2 3
:
OA
对角线OB AD, 相交于点 M .
(1)求OB 和OM 的值;
(2)求直线OD 所对应的函数关系式;
(3)已知点 P 在线段OB 上( P 不与点O B, 重合),经过点 A 和点 P 的直线交梯形OABD 的边于点 E
内的部分的面积为 S ,求 S 关于t 的函数关系式.
( E 异于点 A ),设OP t ,梯形OABD 被夹在 OAE
BM MO
1: 2
,
.
y
B
D
M
O
A
(第 26 题)
x
参考答案
一、选择题(本大题有 7 题,每小题 3 分,共 21 分)
1.A
二、填空题(本大题有 10 小题,每小题 4 分,共 40 分)
6.D
2.C
3.B
4.C
5.B
7.D
8.
1.74 10
4
9.12n
10.9
11. 6
12. 2
3x
13.
k ≤
4
14. 2πr
15.8
16.18
17.2,18
三、解答题(本大题有 9 小题,共 89 分)
18.解:原式
x
1)(
(
x
x
1)
1)
2
(
x x
x
·································································4 分
··········································································································6 分
1
1x
当 2
x 时,原式 1 .·····················································································7 分
19.解:(1)
第一次
第二次
2
1
3
2
3
3
2
4
2
3
4
1
4
1
4
1
·························6 分
.············································································· 8 分
1
6
中,
(2) P (积为奇数)
20.解:在 Rt ACE△
tan
AE CE
tan
DB
···························· 4 分
A
E
B
C
D
(第 20 题)
25 tan 22
···························6 分
10.10≈
·······························································································8 分
AB AE BE AE CD
答:电线杆的高度约为 11.3 米.········································································ 9 分
21.解:根据题意得: (
··················································· 4 分
≈ (米)
30)(100 2 )
x
10.10 1.20
11.3
200
x
整理得: 2 80
x
x
1600 0
············································································ 6 分
x
(
2
40)
,
0
x
40
(元)·········································································7 分
p
100 2
x
(件)···············································································8 分
20
答:每件商品的售价应定为 40 元,每天要销售这种商品 20 件.·······························9 分
22.解:(1)设反比例函数关系式为
y
,
k
x
反比例函数图象经过点 ( 2
P , .
1)
y
P
-2
2
1
-1
-1
-2
O
1 2
Q
x
2
k .···················································· 2 分
.·························· 3 分
反比例函数关第式
y
2
x
2
x
)
y
Q
m, 在
上,
(2)点 (1
m .··································································································· 5 分
(1
Q
, .··································································································6 分
2
2)
(3)示意图.································································································ 8 分
1x 时,一次函数的值大于反比例函数的值.······························· 10 分
当
x 或 0
2
,
C
23.(1)证明: AB AC
B
.······························································································· 1 分
又OP OB
,
B
································································································· 2 分
OPB
.··························································································· 3 分
AD
∥ ·································································································· 4 分
OPB
C
OP
又 PD AC
于 D ,
ADP
90
,
90
DPO
.··························································································· 5 分
PD 是 O 的切线.······················································································6 分
(2)连结 AP , AB 是直径,
,······························· 8 分
C
P
APB
90
AB AC
,
2
CAB
120
,
D
A
O
B
BAP
60
.···························································································· 9 分
,
BC
BP
3
2 3
.············································································· 10 分
24.解:(1)依题意得:
2
( 1)
(
b
1)( 1)
,·········································2 分
2
b
c
2
b c .······························································································· 3 分
(2)当 3b 时,
c ,·············································································· 4 分
5 (
5
1)
2
6
y
x
x
x
2
2
抛物线的顶点坐标是 ( 1
6)
, .······································································ 6 分
(3)当 3b 时,抛物线对称轴
x
b
1
2
,
1
对称轴在点 P 的左侧.
因为抛物线是轴对称图形, ( 1
P
, 且
2 )
b
BP
2
PA
.
, ························································· 9 分
B
( 3
2 )
b
y
O
x
B
P A
b
2
1
.
2
5b .····························································· 10 分
又
c .·············································································· 11 分
b c ,
2
7
抛物线所对应的二次函数关系式
解法 2:(3)当 3b 时,
x
b
2
x
4
x
.············································ 12 分
7
,
1
y
1
2
对称轴在点 P 的左侧.因为抛物线是轴对称图形,
,
, ,且
( 1
( 3
2 )
b
2 )
b
BP
PA
P
B
2
, ······················································· 9 分
2
2)
( 3)
2
b
b c ,解得: 5
,
3(
b
2
b
c
c
又
.········································································· 10 分
7
································································· 11 分
这条抛物线对应的二次函数关系式是
2
4
x
.······································ 12 分
7
x
,
y
2
b
c
,
解法 3:(3)
(
b
b c
1)
2
2
y
2
x
x b
·················································································7 分
BP
x∥ 轴, 2
x
(
b
1)
x b
2
2
b
···························································· 8 分
即: 2
x
(
b
1)
x b
.
2 0
x
解得: 1
1
x
,
2
(
b
2)
,即
Bx
(
b
2)
················································· 10 分
由
BP
2
PA
, 1 (
b
2)
.
2 1
b
5
,
c
7
···························································································· 11 分
这条抛物线对应的二次函数关系式
y
2
x
4
x
············································ 12 分
7
25.解:(1)连结 EF 交 AC 于O ,
当顶点 A 与C 重合时,折痕 EF 垂直平分 AC ,
A
E
D
,
90
AOE
COF
OA OC
∽△
FCO
,
COF
·····················1 分
在平行四边形 ABCD 中, AD BC∥ ,
EAO
AOE
△
··································································································· 2 分
四边形 AFCE 是菱形.················································································· 3 分
(2)四边形 AFCE 是菱形,
设 AB x , BF y ,
AF AE
90
B
OE OF
.
PO
10
.
,
C
F
B
2
x
x
(
2
y
100
······························································································ 4 分
2
y
)
2
xy
100
①