2022-2023学年第二学期练习(一)
数学试卷参考答案及评分标准
说明:本评分标准每题给出了一种或几种解法供参考.如果考生的解法与本解答不同,参照本
评分标准的精神给分.
一、选择题(本大题共 6小题,每小题 2分,共 12分)
题号 1 2 3 4 5 6
答案 A D C D B B
二、填空题(本大题共 10小题,每小题 2分,共 20分)
07 5 2.4,-4 08.x≥3 09.1.2×105 10. 11.1
2
12.55 13.y1>y2>y3 14.75° 15.9 16.5 3
三、解答题(本大题共 11小题,共 88分)
17.(本题 7分)
m-3 m 2 5解: ÷ + -
2m-4 m-2
m-3 m2-4 5
= ÷ -
2m-4 m-2 m-2
m-3 m2-9
= ÷ ·························································································· 3分
2m-4 m-2
m-3 m-2
= · ·············································································· 5分
2(m-2) (m+3)(m-3)
1
= . ································································································ 7分
2(m+3)
18.(本题 7分)
解:解不等式①,得 x<1.·············································································· 2分
1
解不等式②,得 x≥- .················································································· 5分
2
1
所以,不等式组的解集是- ≤x<1.································································· 7分
2
19.(本题 8分)
解:设年平均增长率为 x.
由题意,得 10(1+x)2=14.4.············································································ 4分
解,得 x1=0.2 ,x2=-1.2(舍去).··································································· 7分
答:年平均增长率为 20%.···············································································8分
数学试卷 第 1 页 (共 5 页)
20.(本题 8分)
解:(1)10 000;4 500.···················································································4分
(2)18 000.·································································································· 6分
(3)本题答案不惟一,下列答案供参考.例如,与 2018年相比,2022年该市中学生
3分钟跳绳成绩合格率上升了 15%.····························································· 8分
21.(本题 8分)
1
解:(1).···································································································· 2分
2
(2)将《流浪地球 2》记为 A,《满江红》记为 B.甲、乙、丙三人所有可能的观影选择
有:(A,A,A)、(A,A,B)、(A,B,A)、(A,B,B)、(B,A,A)、(B,A,B)、
(B,B,A)、(B,B,B),共有 8种结果,它们出现的可能性相同.满足甲、乙、
丙三人选择同一部电影(记为事件M)的结果有 2种,即(A,A,A)、(B,B,B),
P M 2 1所以 ( )= = .············································································· 8分
8 4
22.(本题 7分)
作法一:如图 1,
1.作直径 AB的垂直平分线 CO;······································································ 3分
2.分别作∠COA、∠COB的角平分线分别交⊙O于点 Q、P;·································5分
3.分别过点 Q、P作 QM⊥AB,PN⊥AB,垂足分别为 M、N.······························· 7分
则四边形 MNPQ为求作的矩形.
作法二:如图 2,
1.作直径 AB的垂直平分线 CO;······································································ 3分
2.在直线 AB上取两点 D、E,使 OD=OE,并在半圆同侧作矩形 GDEF,使得 DG=OD
3.作直线 GO,FO分别交⊙O于点 Q、P;·························································5分
4.分别过点 Q、P作 QM⊥AB,PN⊥AB,垂足分别为 M、N;······························· 7分
则四边形 MNPQ为求作的矩形.
C C
Q P G F
Q P
A M O N B D A M O N B E
图 2
图 1
无文字说明,作图正确给满分.
数学试卷 第 2 页 (共 5 页)
23.(本题 8分)
解:(1)100,800;···················································································· 2分
(2)600÷3=200(m/min),1 400÷200=7(min),14-7=7(min),
则 C点坐标为(7,0).
设 y=kx+b,把点 C(7,0)、D(14,1 400)代入得
0=7k+b,
1 400=14k+b.
解得 k=200,b=-1 400.
所以 y=200x-1 400;················································································· 5分
(3 2) 或 4或 10.························································································8分
3
24.(本题 9分)
解:(1)∵ AC=BC, A
∴ ∠A=∠B.
∵ DF∥BC,
∴ ∠ADF=∠B.
∴ ∠A=∠ADF. O
D G
∵ A⌒F=A⌒F, F
∴ ∠ADF=∠ACF. B E C
∴ ∠A=∠ACF.
(第 24题)
∴ AB∥CF.
∴ 四边形 DBCF是平行四边形.
∴ BC=DF.
∵ AC=BC,
∴ AC=DF.······························································································· 5分
(2)连接 DE. A
∵ 四边形 DBCF是平行四边形,
∴ BD=CF=3.
∵ 四边形 ADEC是圆内接四边形,
∴ ∠A+∠DEC=180°, O
D G
又∠BED+∠DEC=180°, F
∴ ∠A=∠BED. B E C
∵ ∠B=∠B,
(第 24题)
∴ △EBD∽△ABC.
BE BD BE 3
∴ = ,即 = .
AB BC 12 10
∴ BE=3.6.································································································ 9分
数学试卷 第 3 页 (共 5 页)
C
25.(本题 8分)
M A
解:设广告牌 AC的高度为 x 11°米.
在 Rt△CAM中,∠CMA=11°,
∵ tan11° CA= ,
MA
CA
∴ MA= =5x.
tan11° 63°60°
∵ 四边形 MNBA是矩形, 乙 N F B甲
∴ NB=MA=5x. (第 25题)
∵ NF=10,∴ FB=10-5x.········································································3分
在 Rt△ABF中,∠AFB=60°,
∵ tan60° AB= ,
FB
∴ AB=FB×tan60°= 3(10-5x).
在 Rt△CBF中,∠CFB=63°,
∵tan63° CB= ,
FB
∴CB=FB×tan63°=(10-5x)tan63°.
∵CB-AB=CA,
∴(10-5x)tan63°- 3(10-5x)=x.·····································································6分
解得,x=6.
答:广告牌 AC的高度为 6米. ········································································ 8分
26.(本题 9分)
解:(1)(0,4);(6,4);··············································································· 4分
(2)若 m<0时,由题意得 a>0,b>0,c>0,与题意 abc<0不符.······················6分
-6m
若 m>0,则 x=- =3时,y最小值为 b.
2m
∵ abc<0,∴ b<0.
∵ 点(1,a),(3,b),(4,c)在函数 y=mx2-6mx+4 图象上,
∴ a=-5m+4,b=-9m+4,c=-8m+4.
∴ -9m+4<0 4.解得 m> .
9
-5m+4>0,
①a 1>0,c>0即 解得 m< .
-8m+4>0. 2
-5m+4<0,
a 0 c 0 m 4② < , < 即 解得 > .
-8m+4<0. 5
4 1 4
综上所述, <m< 或m> .············································································9分
9 2 5
数学试卷 第 4 页 (共 5 页)
27.(本题 9分)
(1)∵ AB=AC, A
P
∴ ∠B=∠C.
∵ ∠PMN=∠B, N
∴ ∠PMN=∠C
∵ ∠PMB=180°-∠PMN-∠CMN,
∠MNC=180°-∠C-∠CMN. B M C
∴ ∠PMB=∠MNC.
∵ PM=MN,
∴ △BPM≌△CMN.
∴ BM=CN;·······························································································4分
(2) 2-1≤BM≤1;······················································································ 6分
(3)当 m≥n时,0≤BM≤n;
当 m<n时,n-m≤BM≤m.············································································9分
数学试卷 第 5 页 (共 5 页)2022-2023学年第二学期练习(一)
九年级数学
注意事项:
1.本试卷共6页,全卷满分120分,考试时间为120分钟,考生答题全部答在答题卡上,答在本试卷上无效.
2.请认真核对监考教师在答题卡上所粘贴条形码的姓名、考试证号是否与本人相符合,再将自己的姓名、考试证号用0.5毫米黑色墨水签字笔填写在答题卡及本试卷上.
3.答选择题必须用2B铅笔将答题卡上对应的答案标号涂黑,如需改动,请用橡皮擦干净后,再选涂其他答案.答非选择题必须用0.5毫米黑色墨水签字笔写在答题卡上的指定位置,在其他位置答题一律无效.
4.作图必须用2B铅笔作答,并请加黑加粗,描写清楚.
一、选择题(本大题共6小题,每小题2分,共12分.在每小题所给出的四个选项中,恰有一项是符合题目要求的,请将正确选项前的字母代号填涂在答题卡相应位置上)
1.的值等于( )
A.0.3 B.±0.3 C.0.03 D.±0.03
2.下列计算中,结果正确的是( )
A. B. C. D.
3.如图,数轴上点A表示的数可能是( )
A. B. C. D.
4.在献爱心活动中,五名同学捐款数分别是20,20,30,40,40(单元:元),后来每人追加了10元.追加后的5个数据与之前的5个数据相比,不变的是( )
A.平均数 B.众数 C.中位数 D.方差
5.在正方形网格中,点A、B、C的位置如图所示,建立适当的直角坐标系后,点B,C的坐标分别是,,则点A在( )
A.第一象限 B.第二象限 C.第三象限 D.第四象限
6.如图,在菱形纸片ABCD中,,,分别剪出扇形ABC和⊙O,恰好能作为一个圆锥的侧面和底面.若点O在BD上,则BO的最大值是( )
A. B. C. D.
二、填空题(本大题共10小题,每小题2分,共20分,请把答案填写在答题卡相应位置上)
7.______,______.
8.若式子在实数范围内有意义,则x的取值范围是______.
9.2022年江苏省的GDP突破了120 000亿元,经济总量再上新台阶.用科学记数法表示120 000是______.
10.计算的结果是______.
11.设,是方程的两个根,则______.
12.某商场出售甲、乙、丙三种型号的商品,若购买甲2件,乙3件,丙1件,共需130元;购买甲3件,乙5件,丙1件,共需205元.若购买甲,乙,丙各1件,则需______元.
13.已知,点,,在反比例函数(k为常数,)的图像上,则,,的大小关系是______.(用“>”连接)
14.如图,点A,B,C,D在⊙O上.若,则______°.
15.如图,将边长为40cm的正方形ABCD折叠,使得D点落在BC上的点E处.若折痕FG的长为41cm,则______cm.
16.如图①,有一个圆柱形的玻璃杯,底面直径AB是30cm,杯内装有一些溶液.如图②,将玻璃杯绕点B倾斜,液面恰好到达容器顶端时,AB与水平线l的夹角为30°.则图①中液面距离容器顶端______cm.
三、解答题(本大题共11小题,共88分.请在答题卡指定区域内作答,解答时应写出文字说明,证明过程或演算步骤)
17.(7分)计算.
18.(7分)解不等式组.
19.(8分)为落实“书香中国”的发展战略,某图书馆2022年藏书量为10万册,计划到2024年藏书量达到14.4万册.求图书馆藏书量的年平均增长率.
20.(8分)为了了解2022年某地区5万名大、中、小学生3分钟跳绳成绩情况,教育部门从这三类学生群体中各抽取了20%的学生进行检测.整理样本数据,并结合2018年抽样结果,得到下列统计图.
(1)本次检测抽取了大、中、小学生共______名,其中小学生______;
(2)根据抽样的结果,估计2022年该地区5万名大、中、小学生,3分钟跳绳成绩合格的中学生人数为______名;
(3)比较2018年与2022年抽样学生3分钟跳绳成绩合格率情况,写出一条正确的结论.
21.(8分)2023年春节档电影票房火爆,电影《流浪地球2》和《满江红》深受观众喜爱.甲、乙、丙三人从这两部电影中任意选择一部观看.
(1)甲选择《流浪地球2》的概率是______.
(2)求甲、乙、丙三人选择同一部电影的概率.
22.(7分)如图,已知AB为半圆的直径.求作矩形MNPQ,使得点M,N在AB上,点P,Q在半圆上,且.
要求:(1)用直尺和圆规作图;
(2)保留作图的痕迹,写出必要的文字说明.
23.(8分)如图①,小明家,妈妈的单位和超市在一条直线上,一天傍晚,小明从家步行去超市,与此同时妈妈从单位骑行回家拿东西,再以相同的速度骑行去超市.如图②,线段OD和折线ABCD分别表示小明和妈妈离家的距离y(m)与出发时间x(min)的关系.
(1)小明步行的速度是______m/min,妈妈的单位距离超市______m;
(2)求线段CD所表示的y与x之间的函数表达式;
(3)当______时,小明与妈妈相距400m.
24.(9分)如图,在中,,D是AB上一点,⊙O经过点A,C,D,交BC于点E.过点D作,分别交AC于点G,⊙O于点F.
(1)求证;
(2)若,,,求BE的长.
25.(8分)如图,甲楼AB和乙楼MN高度相等,甲楼顶部有一竖直广告牌AC.从乙楼顶部M处测得C的仰角为11°,从与N点相距10m的F处测得A,C的仰角分别为60°,63°.求广告牌AC的高度.(参考数据:,,)
26.(9分)已知二次函数(m为常数).
(1)不论m为何值,该函数的图像都会经过两个定点,这两个定点的坐标分别为______,______;
(2)若点,,在该函数图像上,当时,求m的取值范围.
27.(9分)如图,在中,.的顶点P,M,N分别在AB,BC,AC上运动,且,.
(1)求证;
(2)若,,则BM的取值范围是______;
(3)已知,,直接写出BM的取值范围(用含m,n的式子表示).
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