山西省晋中市榆次区2024年中考二模数学试卷(PDF版含答案)

资源下载
  1. 二一教育资源

山西省晋中市榆次区2024年中考二模数学试卷(PDF版含答案)

资源简介

榆次区2024年九年级第二次模拟测试题(卷)
数学


准考证号
注意事项:
1.本试卷共8页,满分120分,考试时间120分钟
2.答卷前,考生务必将自己的姓名,准考证号填写在本试卷相应的位置,
3.答案全部在答题卡上完成,答在本试卷上无效
4考试结束后,将本试卷和答题卡一并交回.
一、选择题(本大题共10个小题,每小题3分,共30分.在每个小题给出的
四个选项中,只有一项符合题目要求,请选出并在答题卡上将该项涂黑)
1,有理数-1的相反数是
A月
B
C.-2
D.2
2近年来,全球新能源汽车发展如火如茶,我国新能源汽车产业异军突起,
2024年1至2月,我国新能源汽车销量占世界新能源汽车销量的62%.下
列图案是我国四款新能源汽车的标志,其中既是轴对称图形又是中心对称
图形的是
B
3.下列运算正确的是
A.a2ta=as
B.(-a2)3=-a
C.5-√5=2
D.V6xV3=3√2
4.小明五一假期在某博物馆看到了如图1所示
的展品,了解到它是我国古代官仓、粮栈、
米行等进行粮食计量的必备工具—米斗,
凝聚着中国人上千年的智慧和匠心精神,且
正面
有着吉祥的寓意,是丰饶富足的象征.其示
图1
图2
意图(不记厚度)如图2所示,则其俯视图为
九年级数学试题第1页(共8页)
B
D
5某城市湿地公园的湖中有两个小岛A,B,湖边有一


观景台C(如图),其中观景台C在小岛A的南偏
东30°方向,在小岛B的南偏西50°方向,则∠ACB
的度数是
A.20°
B.50°
C.80°
D.90°
6.随着科技发展,人工智能已经悄然运用在各行各业某款国产人工智能软件
包含文学创作、数理逻辑推算、中文理解、多模态生成等多种功能截至今
年3月,该软件的用户已突破2.13亿,数据2.13亿用科学记数法可以表
示为
A.2.13×107
B.21.3×107
C.21.3×108
D.2.13×108
[2x>4,
7.不等式组
-1≤1
的解集在数轴上表示正确的是
2
012345
012345
01234
012
3
A
B
C
8近几年青少年近视的现象越来越多,为保护视力,
A
某公司推出一款亮度可调节的台灯.我们知道,导
体中的电流I,与导体的电阻R、导体两端的电压
UJ之间满足关系式=R,所以台灯灯光亮度的改
0.2
变,可以通过调节总电阻来控制电流的变化实现。
如图是该台灯的电流I(A)与电阻R(2)成反
1100
R①
比例函数的图象.根据图象可知,下列说法正确的是
A1与R的函数关系式是I=1100
(R>0)
R
B.当R=500时,=2
C.当电阻R(2)越大时,该台灯的电流I(A)也越大
D.当500九年级数学试题第2页(共8页)榆次区 2024 年九年级第二次模拟测试题
数学参考答案及评分细则
一、选择题(本大题共 10 个小题,每小题 3分,共 30 分.)
题号 1 2 3 4 5 6 7 8 9 10
答案 B B D A C D C D C B
二、填空题(本大题共 5个小题,每小题 3分,共 15 分)
x 2 3 15
11. 12. (2 ,1) 13. 14. y 15. 8 5
2 4 x
三、解答题(本大题共 8个小题,共 75 分.)
16.(本题共 2个小题,第 1小题 4分,第二小题 6分,共 10分)
2
(1 1)解: 5 4
3
5 2 9 ······························································3分
2 ···································································· 4分
2x x
(2) 1x2 1 x 1 2x x
解:原方程可化为 1(x 1)(x 1) x 1 ························5分
方程两边同时乘 (x 1)(x 1) 得,
2x x(x 1) (x 1)(x 1). ···························· 7分
1
解,得x .3 ························································9分1
检验:当 x 3时,
(x 1)(x 1) 0.
1
所以原方程的解是x . ····································· 10分
3
17. (本题 6分)
解:设 2023年该村村集体增收为 x 万元,劳务增收为 y 万元.
···························································· 1分
x y 180,
根据题意,得 60%x 50%y 100. ·····················3分
x 100,
解,得 ···························································5分
y 80.
答:2023年该村村集体增收为 100万元,劳务增收为 80万元.···6分
18. (本题 10分)
(1)50 ; ··········································································· 2分
1
(2)
············································································· 4分
(3)80;·············································································· 6分
(4)答案不唯一,选择两个方面言之有理即可.(每个方面 2分)
例如:从平均分看,因为小红同学的成绩为 80分,等于现在总体成绩的平
均分,所以加入小红的成绩后,九(1)班总体成绩的平均分不变.
从众数看,因为加入小红成绩之前,九(1)班总体成绩的众数为 80分,
小红同学的成绩也为 80分,所以加入小红的成绩后,九(1)班总体成绩
的众数不变.
从中位数看,因为加入小红成绩之前,九(1)班总体成绩的中位数为 80
分,加入小红的成绩后,九(1)班总体成绩的中位数仍为 80分,所以加
入小红同学的成绩后,九(1)班的总体成绩的中位数不会发生变化.
从方差看,因为小红同学的成绩为 80 分,等于现在总体成绩的平均分,
加入小红成绩之后,根据方差公式,九(1)班总体成绩的方差会变小.
19. (本题 8分)
解:如图,延长 EF,与直线 AB,CD 分别交于点 G,H.··················1分
由题可得四边形 ACHG 为矩形,GH=AC= 9 m,AG=CH=50 m.
在 Rt△CHF 中,∠CHF=90°,∠FCH=25°,CH=50 m.
tan FCH= FH∴ ∠ .
CH
∴FH CH ·tan∠FCH≈23.5(m),·······4分
在 Rt△EAG 中,∠AGE=90°,∠EAG=20°,AG=50 m.
EG
∴tan∠EAG= .
AG
∴ EG AG ·tan∠EAG≈18(m).·········································· 7分
∴EF=EG+GH-FH≈3.5 (m).
∴该电子屏 EF 的高度约为 3.5 m.············································· 8分
2
20. (本题 9分)
解:(1)A(-3,0),B(1,0),C(0,3);································· 3分
(2)如图,过点 P 作 PE⊥x 轴,交 DB 于点 F,交 x 轴于点 E. 过点 D
作 DQ⊥PE 于点 Q.
∵点 D 为点 C 关于抛物线对称轴的对称点,C(0,3),
抛物线对称轴为直线 x 1 .
∴D(-2,3).································4分
设直线 BD 的函数表达式为 y = kx+b.
将 B(1,0),D(-2,3)分别代入 y = kx+b,
0 k b, k -1,
得 解,得
3 -2k b.

b 1.
∴直线 BD 的函数表达式为 y x 1.······ ······················· 5分
设点 P 的坐标为(m, m 2 2m 3),
∴点 F 的坐标为(m,-m+1).
∵点 P 为直线 DB 上方抛物线上一动点,∴ -2∴PF=( m2 2m 3)-(-m+1)= m2 m 2 .··············6分
S 1 △PDB S△PFD S△PFB PF (DQ BE)2
1 ( m 2 m 2) (x
2 B
xD )
3 (m 1)2 27 .
2 2 8
··············································· ······························· 7分
3
∵ 0 1,∴当m 时,△PDB 的面积最大.············ 8分
2 2
1 15
此时点 P 的坐标为( , ).······································ 9分
2 4
21.(本题 9分)
解:(1)对角线互相平分的四边形是平行四边形;· ·····2分
AO AD
(2)∴ .····································· ·····3分
OG DB
∵CD 是△ABC 中 AB 边上的中线,∴AD=DB.
3
∴OA=OG.··························································································4分
∵OE EG, ∴OG=2OE.
∴OA=2OE.···························································· ····························5分
方法二:
∴∠ADO=∠ABG,∠AOD=∠AGB. ∴△ADO∽△ABG.
AO AD
∴ .··········································· ·········· ·········· 3分
AG AB
∵CD 是△ABC 中 AB 边上的中线,∴AB=2AD.
∴AG=2AO. ∴OA=OG.································ ····························4分
∵OE EG, ∴OG=2OE.
∴OA=2OE.···························································· ····························5分
(3)
···························································· 7分
2. ·············································································· 9分
22.(本题 11分)
解:任务一:
120÷5=24,24÷2=12,
∴顶点 A 的坐标为(12,-24), B(24,0)························ 2分
∴设抛物线模具的函数表达式为 y a(x 12)2 24,·················· 4分
1
将 B(24,0)代入 y a(x 12)2 24,解得 a . ················· 5分
6
1
所以抛物线模具的函数表达式为 y (x 12)2 24 1,即 y x 2 4x.
6 6
····························································6分
方法二:
120÷5=24,24÷2=12,
∴顶点 A 的坐标为(12,-24), B(24,0)························ 2分
∴设抛物线模具的函数表达式为 y ax 2 bx ,························· 3分
4
将 A(12,-24),B(24,0)代入 y ax 2 bx ,
24 122 a 12b
1
, a ,
得 解,得 6
0 24
2 a 24b. b 4.························ 5分
1
所以抛物线模具的函数表达式为 y x 2 4x.
6 ···························6分
方法三:
120÷5=24,24÷2=12,
∴顶点 A 的坐标为(12,-24), B(24,0)························ 2分
∴设抛物线模具的函数表达式为 y ax(x 24),······················· 4分
将 A(12,-24)代入 y ax(x 24) 1,解,得 a . ··············· 5分
6
1 1
所以抛物线模具的函数表达式为 y x(x 24) x 2 4x. ·············6分
6 6
任务二:
(24-12)÷2=6,-24+6=-18············································ 7分
将 y=-18 1代入抛物线解析式 y (x 12)2 24得: 18 1 (x 12)2 24,
6 6
解,得 x1 18, x2 6.·························································9分
x1 x2 18 6 12. ························································· 10分
120÷12=10(个).
答:方案二的一排中最多可摆放 10个花边.···························· 11分
23.(本题 12分)
解:(1)在正方形 ABCD 中,∴AD=AB,∠BAD=90°.···· 1分
由旋转得 AH=AG,∠GAH=90°.···················2分 2分
∴∠BAD-∠GAF=∠GAH-∠GAF.
∴∠BAG=∠DAH.······································ 3分
∴△BAG≌△DAH(SAS).··························4分
图 1
∴GB=HD.················································ 5分
(2)四边形 AGFH 为正方形.································6分
5
证明:∵点 E,F 分别是边 AB,AD 的中点,AD=AB,
∴AE=AF.
∵在等腰 Rt△AEF 中,点 G 是 EF 的中点,
1
∴AG⊥EF,AG= EF=GF.····································8分
2
∴∠AGF=90°. 图 2
∴AH∥GF,AH=GF.
∴四边形 AGFH 为平行四边形.······················9分
∵∠GAH=90°,AG=AH,
∴□AGFH 为正方形.································ 10分
( 3 )16 或8 4 2 . ·········································12分
5
备注:15题解法分析:
6

展开更多......

收起↑

资源列表