广东省深圳市实验学校2018-2019学年七年级第二学期期末联考数学试题

适用年级:初一
试卷号:61745

试卷类型:期末
试卷考试时间:2019/8/28

1.单选题(共8题)

1.
下列各式中,是二次根式的是(  )
A.B.C.D.
2.
下列计算正确的是(   )
A.B.C.D.
3.
如图,已知AB=DC,需添加下列(  )条件后,就一定能判定△ABC≌△DCB.
A.AO=BO B.∠ACB=∠DBCB.AC=DBC.BO=CO
4.
如图,一位同学用直尺和圆规作出了△ABC中BC边上的高AD,则一定有(  )
A.PA=PCB.PA=PQC.PQ=PCD.∠QPC=90°
5.
如图,将五个边长都为1cm的正方形按如图所示摆放,其中点A、B、C、D分别是正方形对角线的交点、如果有n个这样大小的正方形这样摆放,则阴影面积的总和是(  )
A.B.C.D.
6.
如图,△ABC的中线BD、CE相交于点O,OF⊥BC,垂足为F,且AB=6,BC=5,AC=3,OF=2,则四边形ADOE的面积是(  )
A.9B.6C.5D.3
7.
如图,是一块直角三角板,,现将三角板叠放在一把直尺上,与直尺的两边分别交于点D,E,AB与直尺的两边分别交于点F,G,若∠1=40°,则∠2的度数为(  )
A.40º B.50ºC.60ºD.70º
8.
下列长度的三条线段,能组成三角形的是(  )
A.3,4,8B.5,6,10C.5,5,11D.5,6,11

2.选择题(共1题)

9.阅读理解

    Students taking Georgia Tech's online Knowledge-Based Artificial Intelligence course received some surprising news. Jill Watson one of the nine teaching assistants(TAs) that had helped them finish the challenging course for the past five months was not a ‘‘she'' but an “it”—an intelligent robot!

    Watson is the brainchild of Ashok Goel, who teaches the popular online course. The Professor-of Computer and Cognitive Science in the School of Interactive Computing came up with the idea as a way to deal with a number of questions posed by students in the online forums(论坛). According to Goel, every time the course is offered, the 300 or so students that enroll post over 10,000 questions which are often repetitive. This led Goel to wonder if a smart robot would handle the questions which require standard responses.

    Having worked' with IBM's Watson technology platform in the, the professor knew it would be ideal for his artificial TA: Jill Watson. The artificial intelligence system that uses natural language processing and machine learning to analyze large amounts of data has even been cleverer than human competitors on the television show. It would therefore easily be able to handle routine questions that required little “thinking”.

    The professor and his team of graduate students began by populating Jill's memory with 40,000 questions and answers from past terms. Then came the testing stage. At first, Jill was not very good and often gave strange answers. It often got stuck on certain keywords. By the end of the semester, Jill had attained enough knowledge and skills to participate in forums without any management from Goel, or the other assistants.

3.填空题(共5题)

10.
已知a+2b=2,a﹣2b=,则a2﹣4b2=_____.
11.
如果一盒圆珠笔有12支,售价24元,用y(元)表示圆珠笔的售价,x表示圆珠笔的支数,那么y与x之间的关系应该是_____.
12.
如图所示的网格是正方形网格,点A,B,C,D均落在格点上,则∠BAC+∠ACD=_____°.
13.
如图,中,的中点,,BC=8,则__________.
14.
若有一条公共边的两个三角形称为一对“共边三角形”,则图中以BC为公共边的“共边三角形”有________对

4.解答题(共6题)

15.
计算题
(1)(3ab)2•(﹣ab3
(2)20182﹣2016×2020(利用乘法公式计算)
(3)﹣12019+(﹣2+﹣(π﹣3.14)0
(4)[2(x+2y)2﹣(x+y)(4x﹣y)﹣9y2]÷(﹣2x),其中x=﹣2,y=
16.
如图,E,F分别是等边△ABC边AB,AC上的点,且AE=CF,CE,BF交于点P.
(1)证明:CE=BF;
(2)求∠BPC的度数.
17.
如图1,点为线段上任意一点(不与点重合),分别以为一腰在的同侧作等腰,连接于点,连接于点交于点,连接.

线段的数量关系为 ;请直接写出
绕点旋转到如图2所示的位置,其他条件不变,探究线段的数量关系,并说明理由;求出此时的度数;
的条件下求证:.
18.
如图,在△中,,垂足为,点上,,垂足为
(1)平行吗?为什么?
(2)如果,且,求的度数.
19.
如图1,在长方形ABCD中,,点P从A出发,沿的路线运动,到D停止;点Q从D点出发,沿路线运动,到A点停止.若P、Q两点同时出发,速度分别为每秒,a秒时P、Q两点同时改变速度,分别变为每秒(P、Q两点速度改变后一直保持此速度,直到停止),如图2是的面积和运动时间(秒)的图象.
(1)求出a值;
(2)设点P已行的路程为,点Q还剩的路程为,请分别求出改变速度后,和运动时间(秒)的关系式;
(3)求P、Q两点都在BC边上,x为何值时P,Q两点相距3cm?
20.
已知,在一个盒子里有红球和白球共10个,它们除颜色外都相同,将它们充分摇匀后,从中随机抽出一个,记下颜色后放回.在摸球活动中得到如下数据:
摸球总次数
50
100
150
200
250
300
350
400
450
500
摸到红球的频数
17
32
44
64
78
    
103
122
136
148
摸到红球的频率
0.34
0.32
0.293
0.32
0.312
0.32
0.294
    
0.302
    
 
(1)请将表格中的数据补齐;
(2)根据上表,完成折线统计图;

(3)请你估计,当摸球次数很大时,摸到红球的频率将会接近    (精确到0.1).
试卷分析
  • 【1】题量占比

    单选题:(8道)

    选择题:(1道)

    填空题:(5道)

    解答题:(6道)

  • 【2】:难度分析

    1星难题:0

    2星难题:0

    3星难题:0

    4星难题:0

    5星难题:0

    6星难题:13

    7星难题:0

    8星难题:3

    9星难题:3