2023 年初中学业质量检查数学试题
参考答案及评分标准
说明:
(一)考生的正确解法与“参考答案”不同时,可参照“参考答案及评分标准”的精神进行评分.
(二)如解答的某一步出现错误,这一错误没有改变后续部分的考查目的,可酌情给分,但原则上不超过后
面应得的分数的二分之一;如属严重的概念性错误,就不给分.
(三)以下解答各行右端所注分数表示正确做完该步应得的累计分数.
一、选择题(每小题 4分,共 40分)
1.B 2.D 3.A 4. C 5.A 6. C 7.D 8.C 9.B 10.D
二、填空题(每小题 4分,共 24分)
11. 如 1(答案不唯一) 12. 0, 1 1 13. 不可能 14.4 15. 16. x3 x2 2 x1
三、解答题(共 86分)
17.(8分)
解:原式 2 3 2 3 7 ································································································· 6分
9 3 3 ············································································································ 8分
(其它解法,请参照以上评分标准)
18.(8分)
a 2 a 2 a 2 a
解:原式 2 ···················································································· 2分 a 1 a 1 a 1
a 2 a 2 a 1 a
2 ······················································································ 3分 a 1 a 2 a 1
a 2 a
········································································································· 4分
a 1 a 1
2
.·················································································································· 5分
a 1
当 a 3 1 2时,原式 ················································································ 6分
3 1 1
2 2 3
.················································································ 8分
3 3
(其它解法,请参照以上评分标准)
19.(8分)
D
证明:∵ ACB ABC,
E C
∴ AB AC,·········································································· 2分
∵ AB∥CE , A B
(第 19题图)
∴ BAD ACE,·············································································································4分
2023 年初中学业质量检查数学试题参考答案 第 1 页 (共 6 页)
AB AC ,
在△ABD与△CAE中, BAD ACE , ·················································································5分
AD CE
∴△ABD≌△CAE S.A.S ,································································································ 6分
∴ AE BD .······················································································································· 8分
(其它解法,请参照以上评分标准)
20.(8分)
证明:∵四边形 ABCD C是矩形, D F P
∴ ADC DAB 90 , AD∥ BC .······································ 2分 E
∵ DAC 30 Q,
A B
∴ ACD 90 30 60 .····················································3分 (第 20题图)
由旋转的性质可得 DAC FAE 30 , ACD E 60 ,·····················································4分
∴ DAE 30 30 60 ,·································································································· 5分
∵ AD∥ BC,
∴ PQE DAE 60 ,····································································································· 6分
∴ QPE 180 60 60 60 ,·························································································· 7分
∴△PQE 是等边三角形.······································································································· 8分
(其它解法,请参照以上评分标准)
21.(8分)
解:(1)80 40% 200 (人);··································································································3分
受调查学生喜欢运动项目条形统计图
(2)补全图形如图所示,
人数(单位:名)
30
360 54 , 80
200
∴扇形统计图中喜欢跳绳的扇形圆心角的度数为 54 . 50
40
30
A B C D 项目
(3)法一:
画出树状图如下: 小张 A B C D
小王 A B C D A B C D A B C D A B C D
······································································································································· 6分
2023 年初中学业质量检查数学试题参考答案 第 2 页 (共 6 页)
共有 16 4 1种等可能结果,其中同时选中相同项目的共有 4种,故 P(项目相同) .
16 4
······································································································································· 8分
法二:
列表如下:
A B C D
A A, A A, B A, C A, D
B B, A B, B B, C B, D
C C, A C, B C, C C, D
D D, A D, B D, C D, D
······································································································································· 6分
4 1
共有 16种等可能结果,其中同时选中相同项目的共有 4种,故 P(项目相同) .
16 4
······································································································································· 8分
(其它解法,请参照以上评分标准)
22.(10分)
解:(1)由表中数据猜想: y是 x的反比例函数.·············································································· 1分
k k
设 y k 0 ,将 x 225, y 40,代入 y ,得 k 225 40 9000,
x x
9000
∴故所求函数关系式为 y .································································································4分
x
(2)由题意得 x 130 y 4500 ,································································································· 6分
9000 9000
把 y 代入,得 x 130 4500,··············································································· 7分
x x
解得 x 260,························································································································ 8分
经检验, x 260是原方程的根,且符合题意.····································· 9分
∴若直销店计划每天的销售利润为 4500元,则其售价应定为 260元.·····10分 A
(其它解法,请参照以上评分标准) O
23.(10分) G
(1)解:如图 1,⊙O是所求作的圆.·············································3分
B M C
(2)延长GO交⊙O于点 F ,连接OB、 BF ,则 F BEG 180 , (第 23题图 1)
又∵ GEM BEG 180 , GEM 45 ,
F A
∴ F GEM 45 , O
∴ BOG 90 , D
∵⊙O与 AM 相切于点G, G
∴ AG OG, AGD 90
B E M C
2023 年初中学业质量检查数学试题参考答案 第 3 页 (共 6 页(第)23题图 2)
∴ AGD BOG ,
∴OB∥ AG,························································································································4分
∴△BOD∽△AGD,
BO OD BO AG
∴ ,即 ,····································································································5分
AG GD OD GD
∵G是△ABC的重心,
∴ AG 2GM ,······················································································································ 6分
又∵ DG GM 1,
∴ AG 2,··························································································································· 7分
BO 2
∴ 2, BO 2OD,·····································································································8分
OD 1
设半径OB OG r ,则OD r 1,
∴ r 2 r 1 ,解得 r 2,······································································································ 9分
S 90 2
2 1
∴ 2 2 2 .·························································································· 10分弓形 360 2
(其它解法,请参照以上评分标准)
24.(13分)
(1)证明:
∵CD与CE 都是⊙O的切线,
∴CD CE ,即△CDE是等腰三角形.·············································A············································3分
(2)如图 1,作 AM 直线 DE M于点M ,作 BN 直线DE 于点 N,
D
则 AMD BNE 90 .
由(1)证得CD CE ,
F O
∴ CDE CED, G C
又∵ CDE ADM , CED BEN ,
E
∴ ADM BEN , B N
∴△AMD∽△BNE ,··············································································(·第···2·4·题···图··1·)······················ 5分
AM AD
∴ ,
BN BE
∵ AD与 AF 都是⊙O的切线,
∴ AD AF ,同理可证 BF BE,····························································································· 6分
∵ AM DE, BN DE, FG DE,
∴ AM ∥ FG∥ BN ,
MG AF AD
∴ ,
GN BF BE
AM MG
∴ ,
BN GN
又∵ AMD BNE 90 ,
∴△AMG∽△BNG ,················································································································7分
∴ AGM BGN ,
∵ FG DE ,
∴ FGM FGN 90 ,
∴ FGM AGM FGN BGN ,
∴ AGF BGF ,即 FG 平分 AGB .························································································8分
(3) AT BF ,理由如下:
2023 年初中学业质量检查数学试题参考答案 第 4 页 (共 6 页)
过点Q作⊙O的切线HK ,分别交 AC、BC于点 H 、K,连接OA、OB、
OK、OH . A
∵ AB与 HK 都是⊙O的切线,∴ AB FQ,HK FQ, D
∴ AB∥ HK , AFO OQH 90 ,∴ BAH AHK 180 H,
T
∵ AB与 AC都是⊙O的切线,
F O Q C
∴OA平分 BAC 1,即 OAH BAH OHA 1,同理可证 AHK ,
2 2
E K
B
∴ OAH OHA 1 BAH AHK 1 180 90 ,
2 2 (第 24题图 2)
∴ AOH 180 OAH OHA 90 ,
∴ HOQ AOF 90 ,
∵ FAO AOF 90 ,∴ HOQ FAO ,
∴△AFO∽△OQH ,··············································································································9分
FO AF
∴ ,又∵ FO OQ,∴ FO2 AF QH ,
QH OQ
FO BF
同理可证得△BFO∽△OQK ,∴ ,即 FO2 BF QK ,
QK OQ
∴ AF QH BF AF QK QK ,即 ,························································································ 11分
BF QH
HQ CQ CQ QK
∵ AB∥ HK ,∴△CHQ∽△CAT ,∴ ,同理可证 ,
AT CT CT TB
HQ QK QK TB
∴ , ,
AT TB HQ AT
AF TB
∴ ,························································································································12分
BF AT
BF AT BF AT
,即 ,
AF BF AT TB AB AB
∴ AT BF .··························································································································· 13分
(其它解法,请参照以上评分标准)
25.(13分)
解:(1)由题意,得 y x n 2 2 4n 7,
令 x 0,则 y n2 3,
∴点 F 的坐标为 0, n2 3 .····································································································· 2分
(2) 2抛物线 y x n 2 4n 7的对称轴为直线 x 2 n,顶点 E的坐标为 2 n, 4n 7 ,
∵当 x 2时, y随 x的增大而减小,
∴ 2 n 2,解得 n 0,········································································································· 3分
∵点 F 在 y轴的正半轴,
∴ n2 3 0,解得 3 n 3,···························································································· 4分
2023 年初中学业质量检查数学试题参考答案 第 5 页 (共 6 页)
∴ 0 n 3 .此时 2 n 0,由点 A的纵坐标为 t 3,得 4n 7 3,解得 n 1;······························ 5分
综上, n的取值范围是1 n 3 .······························································································· 7分
(3)∵ BC∥ AE, y
∴△AQE ∽△CQB, E
EQ AQ C Q
∴ ,
BQ CQ T B A
如图,过点C作CT AB于点T,则 CTB EBA 90 , O x
∵CT ∥QB, D
AQ AB
∴ ,
CQ TB
EQ AB
∴ .···········································································································(·第··2·5·题··图··)······
BQ TB
由题意得抛物线的顶点为 E h, k ,设 AB m m 0 ,则 A m h, m2 k , B h, m2 k ,
由 A m h, m2 k 与 E h, k ,可求得直线 AE的解析式为 y mx mh k,···································9分
故经过点 B h, m2 k 且与直线 AE平行的直线CD的解析式为 y mx mh k m 2 m x h m k ,
············································································································································10分
2 y x h k , 2
联立得 2 ,化简并整理 x h m x h m 0得,·········································11分
y m x h m k
x h 1 5解得 m ,
2
C D 1 5∵ 在 的左侧,∴ xC h m,······················································································ 12分2
EQ AB xA xB xA xB m 5 1∴ .···························································· 13分
BQ TB xB xT xB xC h h 1 5
2
m
2
(其它解法,请参照以上评分标准)
2023 年初中学业质量检查数学试题参考答案 第 6 页 (共 6 页)2023年初中学业质量综合测试
数学试题
(试卷满分:150分:考试时间:120分钟)
友情提示:所有答案必须填写到答题卡相应的位置上。
一、选择题:本题共10小题,每小题4分,共40分。在每小题给出的四个选项中,只有一
顶是符合要求的。
1.到等于
A.3
B.-3
C.±3
D.3
2.据报道,2022年我国机械工业累讨实现营业收入28900000000000元,将
28900000000000用科学记数法表示为
A.2.89×10
B.28.9×1012
C.0.289×104
D,2.89×1013
3.如图是由圆弧及正方形组成的几何图形,则对该几何图形描述正确的是
A.既是轴对称图形,又是中心对称图形
B.不是轴对称图形,而是中心对称图形
C,是轴对称图形,而不是中心对称图形
D.不是轴对称图形,也不是中心对称图形
(第3题图)
4.对于非零实数4,·下列运算正确的是
A.(a)-a
B.(a2)=a
C.a.a3=a
D.a3.a2=a
5.如图是某零件抽象而成的几何体,则该几何体的左视图是
主坝方向
《第5题图)
6.某校欲组建一支33人的鼓号队,需要从初一年段挑选部分身高大小比较均匀的同学参
加,设初一全年段同学身高的平均数和方差分别为x、52,则入选该鼓号队的同学身高
平均数和方差分别为无、,则下列结论一定成立的是
A.xB.x>
C.s2>2
D.22023年初中学业质兰综合测试数学试题第1页共6页
7.我国古代数学家梅毂成在其数学著作《增删算法统宗》有题如下:“群羊一百四十,剪
毛不弹劳,群中有母有羊羔,先剪二羊比较:·大羊剪毛斤二,一十二两羔毛,百五十
斤是根苗,子母各该多少?”其大意是:今有一群羊140只,母羊与羊羔都可以剪毛.首
先剪两只羊的毛后知道:每只大羊可剪毛18两,每只羊羔可剪毛12两.现在总共剪得
羊毛150斤(注:1斤=16两).试问大羊与羊羔各有多少?”若设大羊x只,羊羔y只,
则依题意可列方程组为
A.
x+y=150,
B.
x+y=140,
12x+18y=140×16
112x+18y=150×16
C.
|x+y=150,
D
x+y=140,
18x+12y=140×16
18x+12y=150×16
8.图,在Rt△ABC中,∠ACB=90°,AC=8,BC=6,点G是△ABC的重心,则CG
等于
A哥
8
B.
3
c.
3
D.4
(第8题网)
9.若点A(m,n-3)、B(m+1,-2n)都在一次函数y=-kx+b的x轴下方的图象上,则n的
值可以是
A.3
B.2
C.1
D.0
10.如图,在菱形ABCD中,线段EF经过对角线AC的中点O,
D
交AD于点E,EF⊥BC,垂足为F,将四边形EFCD沿
D
EF翻折得到四边形EFCD',若AD=5,AC=8,
则sin∠AOC的值为
B.
4
(第10思圈
c号
D.
24
25
二、填空题:本题共6小题,每小题4分,共24分。
11.若双曲线y=在第一、三象限,则k可以是
(写出…个k的值即可).
12.直线y=2x-1与y轴的父点坐标是
13.在一个不透明的袋子中装有3个黑球和2个白球,小球除了颜色不同外,其余均完全相
同,现随机从袋子中摸出一个小球,摸到的球恰好是红球,则该事件是
事
件.(填“随机”、“必然”或“不可能”).
2023年初中学业质量综合测试数学试题第2页共6页