以下是小编为大家准备的届九年级数学上册期中试题(附答案),本文共8篇,希望对大家有帮助。

篇1:届九年级数学上册期中试题(附答案)
一、选择题(每小题2分,共16分)
1.A 2.A 3.A 4.D 5.B 6.C 7.C 8.D
二、填空题(每小题3分,共21分)
9. 10.3 11. 12. 13. 14.
三、解答题(本大题共11小题,共78分)
15.原式= (3分)(算式中对一个三角函数值给1分)
=6. (5分)
16.(每小题4分)
(1)∵△= , (3分)
∴方程有两个不相等的实数根. (4分)
(2)∵△= , (3分)
∴方程没有实数根. (4分)
(△的形式对2分,结果对1分,没有形式只有结果不扣分)
17.(每小题5分)
(1)将原方程化为一般式, 得 ,(如果其它都错了,这步对了可以
∵ , 给1分)
∴ . (3分)
∴ , . (5分)
(2) , (如果其它都错了,这步对了可以给1分)
或 , (3分)
∴ , . (5分)
18.设小道的宽为x米,根据题意,得 (1分)
. (3分)
.
或 , (4分)
∴ , (不合题意,舍去). (6分)
答:小道的宽为2米.
19.∵ ,
∴△ABC∽△ADE. (3分)
∴∠BAC=∠DAE. (5分)
∴∠BAC-∠DAC=∠DAE-∠DAC.
∴∠ BAD=∠CAE. (6分)
20.在Rt△ABC中,∵∠CAB=90°-∠DAC=60°,
∴ ,
∴ = = .(3分)
∵ ,
∴ = = . (6分)
答:敌舰与A、B两炮台的距离分别为3 000米和 米. (不写单位,不写答不扣分)
21.设AB=x米,由题意:
在Rt△AD B中,∠ADB=45°,∠ABD=90°,则DB=AB=x.(2分)
在Rt△ACB中,∠ACB=36.2°,∠ABD=90°,CB=x+10,
∴ tan∠ACB=tan36.2°= =0.73, (5分)
由 =0.73,解得x≈27, (7分)
答:教学楼高约为27米. (不写单位,不写答不扣分)
22.(1)如图所示,A1(4,2),B1(2,-4) . (3分)
(图1分,坐标各1分)
(2)如图所示,A2(0,2),B 2(-1,-1). (6分)
(图1分,坐标各1分)
(3)△OA1B1与△O2A2B2是关于点M(-4,2)
为位似中心的位似图形. (8分)
(点M图上位置1分,坐标1分 )
23.探究: 成立.(其他都错,有这步给1分,没有这步不扣分)
∵∠APC=∠BAP+∠B,∠APC=∠APD+∠CPD, (2分)
∴∠BAP+∠B=∠APD+∠CPD. (3分)
∵∠B=∠APD,
∴∠BAP=∠CPD. (4分)
∵∠B=∠C,
∴△ABP∽△PCD. (6分)
∴ , (7分)
∴ (8分)
拓展: (10分)
24.(1)点A 的坐标为(0,3);点B的坐标为(4,0).(2分)
(2)在Rt△AOB中,OA=3,OB=4,∴AB=5. (3分)
∴AP=t,QB=2t,AQ=5-2t.
△APQ与△AOB相似,可能有两种情况:
若△APQ∽△AOB,
则有 ,即 , (4分)
解得 . (5分)
若△APQ∽△ABO,
则有 , 即 , (6分)
解得 .(7分)
(3)∵ , (9分)
∴ . (10分)
(4) = 或 = . (12分)
篇2:届高三化学上册期中试题(附答案)
本试卷可能用到的相对原子质量:H:1 C:12 N:14 0:16 Na:23 Ca:40
Cl:35.5 K:39
一、选择题(本题共10小题,每小题只有一个选项符合题意,每小题2分,共20分)
1.下列叙述正确的是
A.氢氧化铝、碳酸钠都是常见的胃酸中和剂
B.长期摄入肉、蛋、鱼偏多易导致血液偏酸性
C.碘酒中的碘因有还原性而起到杀菌消毒作用
D.碘盐、铁强化酱油等营养强化剂适合所有人食用
2.下列说法不正确的是
A.仅用酸性高锰酸钾溶液可区分苯和甲苯
B.仅用氯化铁溶液可区分苯酚稀溶液和甘油
C.仅用硝酸和硝酸银溶液可验证卤代烃中卤原子的种类
D.仅用溴的四氯化碳溶液可区别液态的植物油和动物油
3.化学与社会、生活密切相关。对下列现象或事实的解释正确的是
现象或事实 解释
A 用热的烧碱溶液洗去镀件油污 Na2C03可直接和油污反应
B 漂白粉在空气中久置变质 漂白粉中的CaCl2与空气中的C02 反应生成CaCO3
C 施肥时,草木灰(有效成分为 K2C03)不能与NH4C1混合使用 K2C03与NH4C1溶液反应生成氨 气会降低氮肥肥效
D FeCl3溶液可用于铜质印刷线路板制作 FeCl3能从含有Cu2+的溶液中置换出铜
4.下列关于右图所示电化学装置的分析正确的是
A.若X为直流电源,Y为铜棒接正极,则Fe棒上镀铜
B.若X为直流电源,Y为碳棒接负极,则Fe棒被保护
C.若X为电流计,Y为锌棒,则SOT移向Fe棒 /
D.若X为导线,Y为铜棒,则Fe棒发生还原反应
5.若往20 mLO.Ol mol • L-1HNO2(弱酸)溶液中逐滴加入一定浓度的烧碱溶液,测得混合溶液的温度变化如下图所示,下列有关说法的是
A.HNO2的电离平衡常数:c点>b点
B. b点混合溶液显酸性:c(Na+ )>c(N02-)>c(H+)>c(OH-)
C.c点混合溶液中:c(OH-)>c(HN02)
D. d点混合溶液中:C(Na+ )>c(OH-)>c(NO-)(OH-)c(H+)
6.下列化合物的俗称与化学式的是
A.绿矾一FeSO4•7H20 B.芒硝一Na2SO 4 •10H2O
C.明矾一Al(SO4)3•12H20 D.胆矾一CuSO4•5H2O
7.火法炼铜首先要焙烧黄铜矿,其反应为:2CuFeS2 + 02=Cu2S+2FeS+S02下列说法正确的是
A.. S02既是氧化产物又是还原产物
B. CuFeS2仅作还原剂,硫元素被氧化
C.每生成1mol Cu2S,有4 mol硫被氧化
D.每转移1.2 mol电子,有0.3 mol硫被氧化
8.能正确表示下列反应的离子方程式为
A.硫化亚铁溶于稀硝酸中:FeS+2H+ =Fe2+ + H2S↑
B. NH4HC03 溶于过量的 NaOH 溶液中:HC03- +OH- =CO32- +H20
C.少量 C02 通入苯酚钠溶液中:2C6H5O-+C02 + H20=2C6H50H+C032-
D. 大理石溶于醋酸中: CaC03 + 2CH5COOH = Ca2+ + 2CH3COO- + C02 ↑ + H20
9.设NA为阿伏加德罗常数的值,下列叙述正确的是
A.标准状况下,33.6 L氟化氢中含有氟原子的数目为1.5 NA
B.常温常压下,7. 0 g乙烯与丙烯的混合物中含有氢原子的数目为NA
C.50 mL 18.4 mol/L浓硫酸与足量铜微热反应,生成S02分子的数目为0.46 NA
D.某密闭容器盛有0. 1 mol N2和0. 3 mol H2,在一定条件下充分反应,转移电子的数目为0.6NA
10.有关NaHC03与Na2C03的性质,下列叙述中的是
A. Na2C03和NaHC03粉末与同浓度的盐酸时,Na2C03因为碱性强,所以与盐酸反应放出气体速度快
B.等物质的量的两种盐与同浓度的盐酸反应,Na2C03所消耗盐酸的体积是 NaHC03的两倍
C.向Na2C03饱和溶液中通人过量CO2,有NaHC03结晶析出
D.Na2C03和NaHC03溶液分别和BaCl2溶液反应,现象不同
二、选择题(本题共10小题,每小题只有一个选项符合题意,每小题3分,共30分)
11.1L某混合溶液中,溶质X、Y浓度都为0.1mol•L-1,向混合溶液中滴加某溶液
Z(0.1 mol• L-1氢氧化钠或硫酸溶液),所得沉淀的物质的量如图所示,则X、Y、Z分别是
A.氯化铝、氯化铁、氢氧化钠
B.氯化铝、氯化镁、氢氧化钠
C.偏铝酸钠、氢氧化钡、硫酸
D.偏铝酸钠、氯化钡、硫酸
12.短周期元素W、X、Y、Z的原子序数依次增加,m、p、r是由这些元素组成的二元化合物。n是元素的单质,通常为黄绿色气体,q的水溶性具有漂白性,0.01 mol•L-1 r溶液的pH为 2,S通常为难溶于水的混合物,上述物质的转换关系如图所示。下列说法正确的是
A.原子半径的大小W
B.元素的非金属性Z>X>Y .
C.Y的氢化物常温常压下为液体
D.X的最高价氧化物的水化物为强酸
13.已知:Fe203(s)+C(s)= C02(g)+2Fe(s) △H = +234.1 kJ•mol-1
C(s) + 02(g) =CO2(g) △H= —393. 5 kJ • mol-1 则 2Fe(s) + O2(g ) = Fe203(s) 的△H是
A. —824.4 kJ•mol-1 B. —627.6 kJ•mol-1
C. -744.7 kJ• mol-1 D. -169.4 kJ• mol-1
14..金属镍有广泛的用途。粗镍中含有少量Fe、Zn、CU、Pt等杂质,可用电解法制备高纯度的镍,下列叙述中正确的是(已知:氧化性Fe2+
A.阳极发生还原反应,其电极反应式:Ni2++2e-=Ni
B.电解过程中,阳极质量的减少与阴极质量的增加相等x
C.电解后,溶液中存在的金属阳离子只有Fe2+和Zn2+
D.电解后,电解槽底部的阳极泥中只有Cu和Pt
15.某模拟“人工树叶”电化学实验装置如右图所示,该装置能将H20和C02转化为O2和燃料(C3H8O)。下列说法正确的是
A.该装置将化学能转化为光能和电能
B.该装置工作时,H+从b极区向a极区迁移
C.每生成1 mol 02,有44g C02被还原
D.a 电极的反应为:3C02+18H+ —18e-=C3H80+5H20
16.将4 mol A气体和2 mol B气体在2 L的容器中混合并在一定条件下发生如下反应:2A(g) + B(g) 3C(g)+4D(s),若经2s后 测得C的浓度为0.9 mol• L-1,现有下列几种说法
①用物质A表示的反应的平均速率为0.3 mol•L-1•s-1
②用物质D表示的反应的平均速率为0.6 mol•L-1•s-1
③2 s时物质A的转化率为30%
④用A、B、C来表示反应速率,其速率之比=2 : 1 : 3
其中正确的是
A.①③④. B.①②③④ C.①②③ D.③④
17.40℃时,在氨一水体系中不断通入C02,各种离子的变化趋势如下图所示,下列说法不正确的是
A.在 pH = 9.0 时,c(NH4+)>c(HCO3-)
>c(NH2 COO-) >c(CO32-)
B.不同pH的溶液中存在关系:c(NH4+)+c(H+)=2c(C0r)+c
C.随着CO2的通入, 不断增大
D.在溶液中pH不断降低的过程中,有含NH2COO-的中间产物生成
18 .常温时向20 mL 0.1 mol. L-1 HA溶液中不断滴入0.1 mol• L-1 NaOH溶液, pH变化如图所示。下列叙述正确的是
A.HA的电离方程式:HA=H+ +A-
B.水的电离程度:a点>b点
C.c点溶液:c(H+)+c(Na+)»c(A-) +c (HA)
D.d 点溶液:c( Na+) >c(A-) >cC0H-) >c(H+)
19.某温度时,BaS04在水中的沉淀溶解平衡曲线如图所示,下列说法正确的是
提示:BaS04(s) Ba2+(aq) + S042- (aq)的平衡常数Ksp=c(Ba2+)•c(SO42-),称为溶度积常数。
A.加入Na2S04可以使溶液由a点变到b点
B.通过蒸发可以使溶液由d点变到c点
C. d点无BaS04沉淀生成
D. a点对应的大于c点对应的Ksp
20.室温下,将一元酸HA的溶液和KOH溶液 等体积混合(忽略体积变化),实验数据如下表:
实验编号 起始浓度/(mol • L-1) 反应后溶液的pH
c(HA) c(KOH)
① 0.1 0.1 9
② x 0.2 7
下列判断不正确的是
A.实验①反应后的溶液中:c(K+)>c(A-)>c(0H-)>c(H+)
B.实验①反应后的溶液中:c(0H->= c(K+)-c(A-)= mol/L
C.实验②反应后的溶液中:c(A-)+K(HA)>0.1 mol/L
D.实验②反应后的溶液中: c(K+) =c(A-)>c(OH-) =c(H+)
第Ⅱ卷(非选择题,共50分)
三、填空题(本题共4小题,共50分)
21.(14分)某实验小组利用如下装置(部分固定装置略)制备氮化钙(Ca3N2),并探究其实验式。
(1) 按图连接好实验装置,检查装置的气密性,方法是 。
(2)反应过程中末端导管必须始终插入试管A的水中,目的是 。
(3)制备氮化钙的操作步骤是:①打开活塞K并通入N2 ;②点燃酒精灯,进行反应; ③反应结束后, ;④拆除装置,取出产物。
(4)上述步骤①中通入N2 —段时间后再点燃酒精灯原因是 ,装置中干燥管后的U形管的作用是 。
(5)数据记录如下:
空瓷舟质量m0/g 瓷舟与钙的质量m1/g 瓷舟与产物的质量m2/g
14.80 1 5.08 15.15
①计算得到实验式CaxN2,其中x= 。
②若通入的N2中混有少量02,请比较x与3的大小,并给出判断依据: 。
22.(12分)研究催化剂对化学反应有重要意义 。为探究催化剂对双氧水分解的催 化效果,某研究小组做了如下实验:
(1)甲同学欲用右图所示实验来证明Mn02
是H202分解反应的催化剂。该实验 (填“能”或“不能”)达到目的,原因是 。
(2)为探究Mn02的量对催化效果的影响,乙同学分别童取50 mL 1% H202加入容器中,在一定质量范围内,加人不同质量的MnO2,测量所得气体体积,数据如下
MnO2的质量/g 0.1 0.2 0.4
40s末O2体积/mL 49 61 86
由此得出的结论是 ,原因是 。
(3)为分析Fe3+和Cu2+对H202分解反应的催化效果,丙同学设计如下实验(三支试 管中均盛有10 mL 5% H202):
试管 I Ⅱ Ⅲ
滴加试剂 5 滴 0.1 mol•L-1 FeCl3 5 滴 0.1 mol•L-1CuCl2 5 滴 0.3 mol•L-1 NaCL
产生气泡情况 较快产生细小气泡 缓慢产生细小气泡 无气泡产生
结论是 ,实验Ⅲ的目的是 。
(4)①査阅资料得知:将作为催化剂的FeCl3溶液加入H202溶液后,溶液中会发生两个氧化还原反应,且两个反应中H202均参加了反应,试从催化剂的角度分析,这两个氧化还原反应的化学方程式分别是 和 (按反应发生的顺序写)。
②在上述实验过程中,分别检测出溶液中有二价锰、二价铁和一价铜,由此得出选择 作为H202分解反应的催化剂需要满足的条件是 。
23. (10分)硅单质及其化合物应 用范围很广。请回答下列问题
(1)制备硅半导体材料必须先得到高纯硅的主要方法,其生产过程 示意图如图所示。
①写出由纯SiHCl3制备高纯硅的化学反应方程式 。
②整个制备过程必须严格控制无水无氧。SiHCl3遇水剧烈反应生成H2Si03、HCl
和另一种物质,写出配平的化学反应方程式 ,H2还原SiHCl3 过程中若混入02,可能引起的后果是 。
(2)硅酸钠水溶液俗称水玻璃。取少量硅酸钠溶液于试管中,逐滴加入饱和氯化铵溶液,振荡。写出实验现象 其产生原因: 。
① 202(g)+N2(g)=N20,(l) △H1
②N2(g)+2H2(g)=N2H4(l) △H2
③ 02(g)+2H2(g) = 2H20( g) △H3
④2N2 H4 (1) + N204 (1) = 3N2 (g) +4H20(g) △H4=-1048.9 kJ/mol
上述反应热效应之间的关系式为△H4= ,联氨和N2O4可作为火箭助推剂,折算在标准状况下的数据,燃爆后气体的体积与燃爆前的体积之比为: 。
N2H4 N2O4
密度/g/cm3 1.004 1.44
(4)联氨为二元弱減,在水中的电离方程式与氨相似,联氨第一步电离反应的平衡
常数值为(已知:N2H4 +H + N2H5+的K=8.7×107;KW=1.0×10-14),.联氨与硫酸形成的酸式盐的化学式为 。
(5)联氨是一种常用的还原剂。向装有少量 AgBr的试管中加入联氨溶液,观察到 的现象是 。联氨可用于处理锅炉水中的氧;防止锅炉被腐蚀,理论上1kg的联氨可除去水中溶解的O2 kg;与使用Na2SO3处理水中溶解的O2相比,联氨的优点是 。
篇3:-学年初一数学上册期中试题附答案
一、选择题(每小题3分,共24分)
1. 比-1大的数是 ( )
A. -3 B. C. 0 D. -1
2. 若3xmy3与-x2yn是同类项,则(-m)n等于 ( )
A. 6 B. -6 C. 8 D. -8
3. 如图是一个正方体展开图,把展开图折叠成正方体后,“你”字一面相对面上的字是 ( )
A. 我 B. 梦 C. 中 D. 国
4. 下面的计算正确的是 ( )
A. 6a-5a=1 B. a+2a2=2a3
C. -(a-b)= -a+b D. 2(a+b) =2a+b
5. 如图,下列说法错误的是 ( )
A. ∠A和∠B是同旁内角 B. ∠A和∠3内错角
C. ∠1和∠3是内错角 D. ∠C和 ∠3是同位角
6. 多项式2xy-3xy2+25的次数及最高次项的系数分别是 ( )
A. 3,-3 B. 2,-3 C. 5,-3 D. 2,3
7. 如图,甲从A点出发向北偏东70°方向走至点B,乙从A点出发向南偏西15°方向走至C,则∠BAC的度数是 ( )
A. 85° B. 160° C. 125° D. 105°
8. 礼堂第一排有m个座位,后面每排比前一排多一个座位,则第n排的座位个数有( )
A. m+n B. mn+1
C. m+(n-1) D. n+(n+1)
西
二、填空题(每小题3分,共24分)
9. 换算(50 )0= 度 分
10. 将2.95用四舍五入法精确到十分位,其近似值为 。
11. 如图,直线AB、CD相交于点E,DF∥AB,若∠D =65°,则∠AEC= 。
12. 某省进入全民医保改革3年来,共投入36400000元,将36400000用科学记数法表示为 。
13. 若∠1=35°21′,则∠1的余角是 。
14. 如图,直线AB、CD相交于点O,若∠BOD=40°,OA平分∠COE,则∠AOE=
15. A、B、C三点在同一条直线上,M、N分别为AB、BC的中点,且AB=60,BC=40,则MN的长为
16. 下午2点30分时,时钟的分针与时针夹角的度数为 。
三、解答题(共72分)
17. (每小题5分,共10分)计算
(1) (2)
18. (6分)先化简,再求值:
19. (每小题5分 ,共10分)画图:
(1) 画出圆锥的三视图。 (2)已知∠AOB,用直尺和圆规做
(要求:不写作
法 ,保留作图痕迹)
A
20. (5分)一个多项式减去多项式 ,糊涂同学将减号抄成了加号,运算结果为 ,求原题的正确结果。
21. (5分)如果关于 的单项式 与单项式 是同类项,并且 ,当m 的倒数是-1,n的相反数是 时,求 的值。
22. (6分)如图,已知,线段AB=6,点C是AB的中点,点D是线段AC上的点,且DC= AC,求线段BD的长。
23. (6分)如图,直线AB、CD相交于点O,OE平分∠BOD,∠AOC=72°,OF⊥CD,垂足为O,求∠EOF的度数。
24.(6分)如图,已知直线a∥b,∠3=131°,求∠1、∠2的度数(填理由或数学式)
解:∵ ∠3=131°( )
又∵ ∠3=∠1 ( )
∴ ∠1=( )( )
∵ a∥b( )
∴ ∠1+∠2=180°( )
∴ ∠2=( )( )
25. (8分)已知DB∥FG ∥EC,∠ABD=84°,∠ACE=60°,AP是∠BAC的平分线,求∠PAG的度数。
26. (10分)为了节约用水,某市规定三口之家每月标准用水量为15立方米,超过部分加价收费,假设不超过部分水费为1.5元/立方米,超过部分水费为3元/立方米。
(1)当每月用水量为a立方米时,请用代数式分别表示这家按标准用水量和超出标 准用水时各应缴纳的水费;
(2)如果甲、乙两家用水量分别为10立方米和20立方米,那么甲、乙两家该月应各交多少水费?
(3)当丁家本月交水费46.5元时,那么丁家该月用水多少立方米?
七年级数学试卷答案
一、选择题(每小题 3分,共24分)
1. C 2. D 3. B 4. C 5. B 6. A 7. C 8. C
二、填空题:
9、50 30 10、3.0 11、115° 12、3.64×107
13、54°39′ 14、40° 15、50或10 16、105°
三、解答题:
17. (1) (2)
=4-4-3-2………………3分 = ……1分
=-5…………………………5分 = ……3分
= ……………………4分
=
18. 19.(1)
=
= ………………3分
当 时代入
原式= =3×12×(-1)=-3
……………………6分
19.(1)
……1.5分 3分
………………5分
19.(2)
所以 ∠ 为所画的角
20.
21. m=-1…………1分
n= …………2分
C=3 …………3分
2a+3b=0…………4分
(2a+3b)99+mc-nc
=099+(-1)3-
= ………………5分
23. ∵ ∠BOD=∠AOC=72°………1分
又∵OE平分∠BOD
∴ ∠DOE= ∠BOC=36°……3分
∵ OF⊥CD
∴ ∠FOD=90° …………4 分
∴ ∠FOE=∠FOE-∠EOD
=90°-36°=54°……6分
25. ∵ CE∥FG
∴ ∠GAC=∠ACE=60°…………2分
∵ DB∥FG
∴ ∠BAG=∠DBA=84°…………4分
∴∠BAC=60°+84°=144°……5分
∵ AP平分∠BAC
∴∠PAC= ∠BAC=72°……6分
∴ ∠PAG=72°-60°=12°……8分
22. ∵ C是线段AB的中点
∴ BC=AC= …2分
∵ DC= ……4分
∴ BD=CD+BC=1+3=4…………6分
24. (已知)…………1分
(对顶角相等)…………2分
(131°)(等量代换)……3分
(已知)………………4分
(两直线平行,同旁内角互补)…5分
(49°)(等式的性质)……6分
26. (1)当0
当a>15时 1.5×15+3(a-15)
=(3a-22.5)元…………4分
(2)当a=10时 1.5a=1.5×10=15(元)6分
a=20时,3a-22.5=3×20-22.5=37.5元 8分
(3)15+(46.5-15×1.5)÷3=23(立方米)
…………………………10分
篇4:九年级上册数学期中知识要点测试题及答案
九年级上册数学期中测试题及答案
一、选择题(每小题3分,共24分)
1.下列各式中,y是x的二次函数的个数为(A)
①y=2x2+2x+5;②y=-5+8x-x2;③y=(3x+2)(4x-3)-12x2;④y=ax2+bx+c;⑤y=mx2+x;⑥y=bx2+1(b为常数,b≠0).
A.3B.4C.5D.6
2.把160元的电器连续两次降价后的价格为y元,若平均每次降价的百分率是x,则y与x的函数关系式为(D)
A.y=320(x-1)B.y=320(1-x)C.y=160(1-x2)D.y=160(1-x)2
3、下列方程中是关于x的一元二次方程的是(C)
A.x2+1x2=1B.ax2+bx+c=0C.(x-1)(x+2)=1D.3x2-2xy-5y2=0
4、若x1,x2是一元二次方程x2-5x+6=0的两个根,则x1+x2的值是(B)
A.1B.5C.-5D.6
5、在平面直角坐标系中,与点(2,-3)关于原点中心对称的点是(C)
A.(-3,2)B.(3,-2)C.(-2,3)D.(2,3)
6、下列事件中,属于旋转运动的是(B)
A.小明向北走了4米B.小朋友们在荡秋千时做的运动
C.电梯从1楼到12楼D.一物体从高空坠下
7、下列四个命题中,正确的个数是(C)
①经过三点一定可以画圆;
②任意一个三角形一定有一个外接圆,而且只有一个外接圆;
③任意一个圆一定有一个内接三角形,而且只有一个内接三角形;
④三角形的外心到三角形三个顶点的距离都相等.
A.4个B.3个C.2个D.1个
8、圆锥形烟囱帽的底面直径为80cm,母线长为50cm,则此烟囱帽的侧面积是(C)
A.4000πcm2B.3600πcm2C.πcm2D.1000πcm2
二、填空(每小题3分,共24分)
9、若一元二次方程ax2+bx+c=0的两个根是-3和1,那么二次函数y=ax2+bx+c与x轴的交点是(-3,0)(1,0)
10、一个正方形的面积是25cm2,当边长增加acm时,正方形的面积为Scm2,则S关于a的函数关系式为S=(5+a)2
11、制造一种产品,原来每件成本是100元,由于连续两次降低成本,现在的成本是81元,则平均每次降低成本的10%
12、读诗词解题(算出周瑜去世时的年龄):周瑜去世时36岁.
大江东去浪淘尽,千古风流人物.而立之年督东吴,早逝英才两位数.
十位恰小个位三,个位平方与寿符.哪位学子算得快,多少年华属周瑜.
13、若△ABC的三边为a,b,c,且点A(|c-2|,1)与点B(b-4,-1)关于原点对称,|a-4|=0,则△ABC是等腰三角形.
14、在数轴上,点A,B对应的数分别为2,x-5x+1,且A,B两点关于原点对称,则x的值为1.
15、已知扇形的圆心角为150°,它所对应的弧长为20πcm,则此扇形的半径是24_cm,面积是240πcm2(结果保留π).
16、正六边形的边心距为3cm,则面积为18cm2
三、解答题
17、(10分)解一元二次方程①x2-x-12=0②(x+1)(x-2)=x+1
x1=4x1=-1
x2=-3x2=3
18、(10分)如图,△ABC三个顶点的坐标分别为
A(-2,3),B(-3,1),C(-1,2).
(1)将△ABC向右平移4个单位,画出平移后的△A1B1C1;
(2)画出△ABC关于x轴对称的△A2B2C2;
(3)将△ABC绕原点O旋转180°,画出旋转后的△A3B3C3;
(4)在△ABC,△A1B1C1,△A2B2C2,△A3B3C3中,△ABC与△A2B2C2_成轴对称,对称轴是x轴;△ABC与△A3B3C3_成中心对称,对称中心是点O_.
19、(10分)曲靖市平均房价为每平方米3600元,连续两年增长后,平均房价达到每平方米4900元,求这两年房价的年平均增长率。
解:设这两年房价的年平均增长率为x、依题意得:
3600(1+x)2=4900
(1+x)2=
1+x=±
X1=X2=-(舍弃)
答:这两年房价的年平均增长率为(16.7%)
20、(10分)抛物线的图像如下,求这条抛物线的解析式。(结果化成一般式)y
Y=-x2+2x+3
21、(10分)如图,已知在⊙O中,AB,CD两弦互相垂直于点E,AB被分成4cm和10cm两段.
(1)求圆心O到CD的距离;
(2)若⊙O半径为8cm,求CD的长是多少?
圆心O到CD的距离:3cm
⊙O半径为8cm,CD的长是2cm
22、(10分)直线AB,CD相交于点O,∠AOC=30°,半径为1cm的⊙P的圆心在射线OA上,开始时,PO=6cm,如果⊙P以1cm/秒的速度沿由A向B的方向移动,那么当⊙P的运动时间t(单位:秒)满足什么条件时,⊙P与直线CD相切?
4秒或8秒
23、(12分)有一座抛物线形拱桥,正常水位时桥下水面宽度为4m,拱顶距离水面2m.
(1)求出这条抛物线表示的函数的解析式;
(2)设正常水位时桥下的水深为2m,为保证过往船只顺利航行,桥下水面的宽度不得小于2m.求水深超过多少m时就会影响过往船只在桥下顺利航行.
解:以桥拱的顶点为原点建立平面直角坐标系
1)这条抛物线表示的函数的解析式为:y=-2
2)当x=1时y=-0.5
-0.5-(-4)=3.5(m)
答:水深超过3.5m时就会影响过往船只在桥下顺利航行
解:以正常水位时水面的中点为原点建立平面直角坐标系
1)这条抛物线表示的函数的解析式为:y=-2+2
2)当x=1时y=1.5
2+1.5=3.5(m)
答:水深超过3.5m时就会影响过往船只在桥下顺利航行
解:以正常水位时水面的左端为原点建立平面直角坐标系
1)这条抛物线表示的函数的解析式为:y=-2+2x
2)当x=1或x=3时y=1.5
2+1.5=3.5(m)
答:水深超过3.5m时就会影响过往船只在桥下顺利航行
解:以正常水位时水面的右端为原点建立平面直角坐标系
1)这条抛物线表示的函数的解析式为:y=-2-2x
2)当x=-1或x=-3时y=1.5
2+1.5=3.5(m)
答:水深超过3.5m时就会影响过往船只在桥下顺利航行
篇5:九年级英语上册期中试题及答案
一. 单项选择 (每小题1分,共15分)
从每小题所给的四个选项中,选出可以填入空白处的最佳答案。
( )1. — This is ______ useful guidebook.
— I agree with you. We may get lost without it.
A. a B. an C. the D. /
( )2. In my opinion, parents should get their kids to face difficulties ____ their own.
A. by B. on C. with D. for
( )3.Mrs Brown, don’t worry about D aming. He is old enough to take care of ______.
A. himself B. herself C. yourself D. itself
( )4. — Amanda, what’s your favourite subject?
— ______, though it’s not easy for me.
A. Autumn B. Chemistry C. Swimming D. Electricity
( )5. — Amy, can you help me look for my pet cat? It went ______ just now.
— Oh, sure.
A. bad B. sick C. wrong D. missi ng
( )6.Where are your dad and brother, Lisa? We’ve been waiting for them for ten minutes.
Well, Dad ______ Tom for losing his glasses in the living room.
A. punishes B. is punishing
C. punished D. will punish
( )7. — Sara, I hear your son is sick.
— Yes, he has had a high fever. That’s why I want to take two days ______.
A. off B. back C. over D. on
( )8.— Xi’an is such a beautiful city. What about ______ here for two more days?
— Good idea. And we can go to visit the Terracotta Army.
A. moving B. leaving C. remaining D. reaching
( )9. Old Tom is unhappy because ______ has visited him since he moved to town.
A. everybody B. somebody C. anybody D. nobody
( )10. More than ______ people visited the ______ car exhibition.
A. two million; eight-day B. two millions; eight days’
C. two millions; eight-day D. two million; eight day’s
( )11. Celia, you’d better ______ the TV now. It’s time to go to bed.
Oh, Mum, the talk show will be over soon. Please give me ten more minutes.
A. turn on B. turn up C. turn off D. turn down
( )12. — Please ______, or you will have to get out of the reading room.
— Oh, sorry.
A. stop shouting B. stop to shoutC. stopping shouting D.stopping to shout
( )13. Mr Green asks us to hand in our reports ______ we finish them.
A. before B. as soon as C. though D. because
( )14. — I’ve decided to go to Las Vegas to spend my summer holiday.
— ______. What about going there together?
A. So do I B. So have I C. So did I D. So will I
( )15. — I came first in the long jump.
— ______. I’m so proud of you.
A. Good luck B. Have fun C. Well done D. You’re joking
二. 完形填空 (每小题1分,共10分)
通读下面的短文,掌握其大意,然后从各小题所给的四个选项中,选出一个最佳答案。
Mr Oliver was the richest man in town. He didn’t have to 16 . All day long the only thing he did was to sit at his window and watch everyone else work hard for a living.
Every 17 Mr Oliver sat at hi s window and waited for people to come home from work. 18 after a busy day, they rested and looked out at the stars and the moon at night. But soon 19 all went to bed, fell asleep and dreamed. After a while, Mr Oliver went to bed, too, 20 he didn’t fall fast asleep.
One night, Mr Oliver heard a 21 at his window. He found a little injured bird on his windowsill (窗台).
“Poor little thing,” Mr Oliver said 22 . “The city is no place for birds.”
He carried the little bird inside and took care of its injured wing (翅膀).
Mr Oliver worked and worked. 23 , he fell asleep with the little bird in his hands. And then he dreamed about a 24 for birds.
The next morning, Mr Oliver hurried outdoors and 25 to work. He wanted to build a beautiful park for birds with trees and beautiful flowers in it.
From that day on, Mr Oliver never had difficulty falling asleep and he became a happy and busy man.
( )16. A. wait B. worry C. work D. drive
( )17. A. morning B. noon C. evening D. night
( )18. A. Hungry B. Tired C. Happy D. Excited
( )19. A. you B. he C. we D. they
( )20. A. because B. but C. so D. if
( )21. A. voice B. knock C. song D. noise
( )22. A. angrily B. sadly C. proudly D. nervously
( )23. A. At last B. First of all C. In fact D. Above all
( )24. A. park B. hospital C. home D. square
( )25. A. forgot B. offered C. began D. agreed
三. 阅读理解 (每小题2分,共40分)
阅读下列材料,完成每篇材料后的问题。
A
October is getting closer and it also means that the year of is coming to an end. “Hooray! It’s a holiday!” While you are thinking of putting textbooks aside and playing video games, let’s take a look at what children in other continents usually do during their holidays.
Children in America don’t have much homework to do. They keep themselves busy by playing camp games. A parent says, “My daughter Shirley usually attends different camps. We don’t ask her to spend plenty of time on maths problems or spelling tests.”
Children in Australia take partin activities on over twenty different th emes (主题). They learn painting, dancing, singing, history, culture and so on. Parents can accompany their kids to enjoy the learning process and to build a closer relationship with them.
These are what African kids do: build a boat, have a camel race, make a drum and make a rag (碎布) football. Don’t you think it is interesting that kids in other places have no idea how to make a drum, but kids in Africa do?
Plan your holiday well and try what you want to try. Make a good plan and you will have a lot of fun.
( )26. Where does Shirley come from?
A. Asia. B. America. C. Australia. D. Africa.
( )27. What does the underlined word “accompany” mean in Chinese?
A. 提醒 B. 监视 C. 陪伴 D. 排斥
( )28. According to the passage, only kids in Africa know how to ______.
A. play camp games B. do spelling testsC. build a boat D. make a drum
( )29. Which of the following is TRUE?
A. The passage was written before October.
B. Kids in America are good at maths.
C. Kids in Australia spend much time on homework.
D. Kids in Africa don’t play football.
( )30. What is the purpose of this pas sage?
A. To advise kids to make holiday plans.
B. To introduce some good holiday camps.
C. To encourage kids to make friends with parents.
D. To show the importance of doing homework during holidays.
B
“Whoosh!” The ball flew into the net and the game was finally over. This game had gone into overtime (加时赛) twice. Until the last goal was scored, no one had any idea which team would win.
Dave felt so bad because his team had lost. He liked playing soccer, but he liked winning even more. Now the two teams should have a picnic together. Dave did not want to eat lunch with the other team. The other team would probably brag (显摆) by talking about how they won the game.
Dave went to the locker room (更衣室) to change out of his soccer clothes. There the coach talked to the team about what they had done well. They also talked about how they could improve. Then everybody walked outside towards the picnic table.
One of the players from the other team was standing near the picnic table. He handed Dave a paper plate. “Hi, I’m Miguel,” he said.
“Hi,” Dave replied, looking down at the ground.
“You played great,” Miguel said. “I didn’t think we were going to win.”
Dave was surprised. Miguel was not bragging at all.
“Thanks,” Dave said to Miguel. “You played great, too.”
Dave felt happy. Dave promised himself that the next time his team won a game, he would not brag to the other team. It was wonderful to win, but it was even more important to be a good winner.
( )31.What happened first in the story?
A. Dave met Miguel. B. The boys ate lunch together.
C. Dave went to the locker room. D. The soccer game ended.
( )32.Which sentence best describes Dave?
A. He didn’t like to lose. B. He got angry a lot.
C. He got tired easily. D. He was not friendly to others.
( )33.What ha ppened in the locker room?
A. Dave and Miguel talked. B. Dave and his team ate lunch.
C. The coach talked to the team. D. Dave put on his soccer clothes.
( )34.What was Dave’s problem?
A. He was too tired to eat. B. He didn’t want to eat with the winning team.
C. He didn’t like Miguel. D. He didn’t play soccer as well as his teammates.
( )35. Based on the story, what would probably happen in the future?
A. Miguel would brag the next time his team won.
B. Dave would not brag the next time his team won.
C. Dave’s team would win the next soccer game.
D. Miguel’s team would not play against Dave’s team again.
C
Kitesurfing as a water sport began in the 1980s, but didn’t get popular until the end of last century. It is also known as kiteboarding, and in some European countries as flysurfing. Kitesurfing works through wind power (动力) by using a large kite to pull a rider on the water at high speed.
At first, kitesurfing was a difficult and dangerous sport. Now it is becoming easier and safer because of the safer kite design. For an able and strong person, kitesurfing can be a very fun, exciting sport, just like skating on the water with a feeling of flying. It has become more and more popular.
Compared with other water sports, kitesurfing is easier to learn. A beginner can understand how to operate the kite with 5-10 hours of training. And anybody aged from 13 to 65 can learn. It is not expensive to get the equipment (装备) for kitesurfing, which costs $1,000 to $2,500. Training lessons range from $200 to $500 for two or three hours. With the development of its equipment progress (进步), kitesurfing is becoming even safer. After some training, you can enjoy its excitement and challenging feeling.
With the rising popularity of kitesurfing, most major seaside cities have kitesurfing clubs. In China, Xiamen is the only place that has the kitesurfing club, which provides professional kitesurfing training and equipments.
( )36.Kitesurfing has a history of about years.
A. 30 B. 50 C. 100 D. 130
( )37. is mentioned in the passage as the power of kitesurfing.
A. Water B. Wind C. The sun D. The kite
( )38.The underlined word “range” in the third paragraph means “ ” in Chinese.
A. 在……范围内变动 B. 按……顺序排列
C. 向……方向延伸 D. 根据……归类
( )39.The most important reason for the popularity of kitesurfing is that .
A. its price is getting lower and lower
B. more and more people are enjoying its excitement
C. its equipment progress makes it easier and safer
D. all people can learn and take part in it
( )40.The main idea of this passage is about .
A. how to operate kitesurfing
B. the progress of kitesurfing equipment
C. the history of kitesurfing in China
D. the development of kitesurfing
D
During a winter storm in 1919, one dog managed to save the lives of the people on the ship Ethie. Today, people still tell the story of the dog.
In December 1919, Ethie was travelling along the coast of northern Canada. Without warning, the ship ran into a bad storm. Because of high winds and heavy snow, the captain could not tell where he was going. Sailing too close to the shore (岸), the ship could not move because of some rocks. Ethie was in danger.
The captain decided to save the people on his ship. He thought it was too dangerous to try to reach the shore by lifeboat, so he sent up flares (闪光信号) to call for help. People saw the flares and rushed to the beach. The crew (船员) tried to throw a rope (绳子) to them, but there seemed to be no way to get a rope to the shore.
In the early 1900s ships often carried a large kind of dog called a Newfoundland. Newfoundlands are excellent swimmers. During sea journeys, Newfoundlands would bring back things that had fallen off the ship or even save people from the sea.
The Newfoundland on Ethie was named Tang. The captain decided that Tang offered their best hope of survival (幸存). He gave the dog a long rope. Holding the rope between his teeth, Tang jumped into the turbulent water. He fought his way through high waves and strong winds. Finally he reached the beach.
The people on the shore took the rope. The rope became the ship’s lifeline.
Because of Tang, all the people on Ethie landed on the beach safely. He was given a special medal for being a hero. Tang wore the medal f or the rest of his life.
( )41.What happened to the ship Ethie at the beginning of the story?
A. It ran into a bad storm. B. It couldn’t reach the shore.
C. There was a hole in it. D. It was found at the bottom of the sea.
( )42.Ethie could not move near the shore because of .
A. the high waves B. the heavy snow
C. some rocks in the sea D. the st rong winds
( )43. Which order is RIGHT according to the story?
① The dog reached the beach.
② The captain gave Tang a rope.
③ Tang was given a special medal.
④ The captain sent up flares.
A. ①③②④ B. ④②①③
C. ①②④③ D. ②④①③
( )44.The word “turbulent” means .
A. rough B. smooth C. safe D. amazing
( )45. Which of the following can be the best title of the passage?
A. A storm in 1919 B. The rope to save people
C. A medal for a dog D. The hero on the ship
四. 补全对话(每小题1分,共5分)
在每小题的空白处选择适当的话语使对话意思完整。
A:Hello, Xiao Hong!
B:Hello!
A: Y ou look a little upset.___________46__________
B: Yes. It’s just my mom. She always nags (唠叨)me.
A:Really? What does your mother nag you about?
B: __47__“Get up now…Everything must be in place…Don’t forget your piano lesson…”
A: Well, all the mothers like saying these words to their children.
B: Also, I’m fond of pop music.___48_ We don’t have the same interest in many things.
A:___49__But I should say she nags you because she cares about you. You’re lucky to have such a good mother.
B: I agree with you. ____50____ .
A: Th at’s right. Understanding is important. If your mom knows that everything is fine, she will never nag.
五. 完成句子 (每小题2分,共10分)
根据中文意思完成句子。
51. 爸爸去上海出差了。
My father has gone to Shanghai ______ _______.
52. 孩子们在假期里玩得非常高兴。
The children _____ great ______ during the vacation.
53. 现在许多人死于吸烟。
Many people ______ _______ smoking now.
54. 作为青少年,我们应该自己洗衣服。
As teenagers , we should wash clothes ______ our _______.
55. 你必须先穿过一条巨大的玻璃金字塔才能到达那幢大楼。
You must ______ _______ a giant glass pyramid first, then you will get to the building.
六、综合填空(本题共10小题;每小题1分,满分10分)
请认真阅读下面短文,并根据各题所给首字母的提示,写出一个合适的英语单词完整、正确的形式,使短文通顺。
Kitty was a student in a small town. It was going to be her mother’s birthday. She wanted to buy her a present that would be nice and useful but not e 56 .
She went s 57 after a quick and simple lunch. After she looked for about forty minutes, she found a shop that was selling cheap umbrellas, and she d 58 to take a black one. She thought, “Mom can carry it when she is wearing clothes of any
c 59 .” So she bought a lovely black umbrella and took it to school with her until her classes finished.
On her way home on the train she felt h 60 , so she went to the buffet car (餐车). She left the umbrella on her seat and left. But when she remembered it and r 61 for it, it was gone. Kitty began to cry. The other passengers felt very sorry for her and asked what was the matter. She told them the black umbrella she bought for her mother was gone, and she had to get off at the next station. After the three passengers h 62 this, they asked her for her mother’s a 63 so that they could send the umbrella to her if someone took it by mistake (弄错) and brought it b 64 .
And now a week passed. Kitty got a letter from her mother. It said, “Thank you very much for your lovely g 65 , but why do you send me three black umbrellas?”
七. 书面表达(满分10分)
假如你是刘红的老师,刘红今天因 病没来上学。请你根据提示和要求给刘红发一封e-mail, 以示关心。
提示:1 不要着急,遵照医嘱休息、吃药
2 以后多锻炼、必须吃早餐、少吃零食、饮食平衡(have a balanced diet)才会健康
要求:
① 80词左右(开头已给出,不计入总词数);
② 文中需包括所有写作要点,但不要逐字翻译,可适当加入过渡词句,使短文通顺、连贯。
Dear Liuhong,
Are you feeling better now?
篇6:九年级英语上册期中试题及答案
1-5 ABABD 6-10 BACDA 11-15 CABBC
16-20 CCBDB 21-25 DBAAC 26-30 BCDAA
31-35 DACBB 36-40 ABACD 41-45 ACBAD
46-50 BDFAC
短文填空(本题共10小题;每小题1分,满分10分)
66. expensive 67. shopping 68. decided 69. colour 70. hungry
71. returned 72. heard 73. address 74. back 75. gifts
One possible version:
All of us are worrying about you. Please don’t worry. We will help you with your lessons. You’d better have a good rest at home and take medicine as the doctor told you. When you feel better, you should do some exercise and eat breakfast everyday. Breakfast is very important for your health. Try to eat fewer snacks. Have a balanced diet every day and you will be strong and healthy.
篇7:七年级数学上册期中试题及答案
一、选择题(30分)
1、如果零上2℃记作+2℃,那么零下3℃记作( )
A. -3℃; B. -2℃; C. +3℃; D. +2℃;
2、-2的倒数是( )
A. ; B. ; C. 2; D. -2;
3、下列判断错误的是( )
A. 1-a-ab是二次三项式; B. –a2b2c与2ca2b2是同类项;
C. 是单项式; D. 的系数是 ;
4、计算︱-2+3×(-2)︱=( )
A. -8; B. 2; C. 4; D. 8;
5、有理数ab在数轴上的位置如图所示,下列式子成立的是( )
A. a>b; B. a
C. ab>0; D. >0;
6、据统计,全国每年因吸烟引起疾病致死的人数大约600万,数据600万用科学记数法表示为( )
A. 0.6×107; B. 6×106; C. 60×105; D. 6×105;
7、计算2xy2+3xy2的结果是( )
A. 5xy2; B. xy2; C. 2x2y4; D. x2y4;
8、从 减去 的一半,应得到( )
A. ; B. ; C. ; D. ;
9、数据4604608取近似值,保留三个有效数字,结果是( )
A. 4.60×106; B. 4600000; C. 4.61×106; D. 4.605×106;
10、已知 ,则 的值是( )
A. -5; B. 15; C. -1; D. 1;
二、填空题(24分)
11、数轴上与表示-3的点的距离为5个单位的点所表示的有理数是 。
12、若实数a、b满足 ,则ab的值为 。
13、一个两位数,个位数字为a,十位上的数轴比个位上的数轴小3,则
这个两位数是 。
14、若 与 是同类项,则m+2n= 。
15、化简 的结果是 。
16、某公交车原来有22人,经过四个站点的上下车情况如下:(上车为正)
(+4,-8)、(-8,+6)、(-3,+2)、(+1,-7)、现在车上有 人。
17、若多项式 是关于a的二次三项式,则m-n= .
18、三个数-10、-7、+5的和比它们的绝对值的和小 。
三、解答题(26分)
19、(12分)(1)
20、(8分)化简:(1)
21、(6分)先化简,再求值:
;其中
四、应用题:(22分)
22、(7分)已知 是关于x、y的多项式,若该多项式不含二次项,试求3a+8b的值。
23、(7分)某银行储蓄员小张在办理业务时,约定存入为正,取出为负。一天他办理了六笔业务:-780元,-650元,+1250元,-310元,-420元,+240元。
(1)若他早上领取备用金5000元,那么下班时应交回银行多少元钱?
(2)若每办一笔业务,银行发给业务量的0.1﹪作为奖励,这天小张应得奖金多少元?
24、(8分)王叔叔家的装修工程接近尾声,经统计,油漆工共做了50工时,用了150升油漆。已知油漆每升128元,共粉刷120平方米,在结算工钱时,有以下几种方案:(1)按工时结算:每6工时300元;(2)按油漆费用结算:油漆费用的15﹪为工钱;(3)按粉刷面积结算:每6平方米132元;请你帮王叔叔算一下,用哪种方案最省钱?
五、综合题(18分)25、图①是生活中常见的日历,观察日历回答问题:
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30
① ②
(1)图②是另一个月的日历,a表示该月中的某一天,b、c、d是该月中的其它3天,b、c、d与a有什么关系?b 、c 、d ;(用含a的式子表示)
(2)用一个长方形框出日历中的三个数(图②中的阴影),如果这三个数之和是51,那么这三个数各是多少?
(3)这样框出的三个数之和可能是64吗?为什么?
26、(10分)按照下列的步骤计算:
用不同的三位数再做几次,结果都是1089吗?你能发现其中的原因吗?
参考答案:
一、选择题:1、A;2、B;3、C;4、D;5、A;6、B;
7、A;8、D;9、A;10、A;
二、填空题:11、2或-8;12、;13、11a-30;14、9;15、x+6y;
16、12;17、-8;18、34;
三、解答题:
19、(1)—73;(2)3;(3) ;
20、(1)原式=
(2)原式=
21、原式=x+y+3,将 代入,原式=
22、由条件知:a-2=0,a=2;b+1=0,b=-1;
3a+8b=3×2+8×(-1)=-2
23、(1)5000—780—650+1250—310—420+240=4330,他下班时应交回4330元。
(2)(780+650+1250+310+420+240)×0.1﹪=3.65元。他应得奖金3.65元。
24、方案(1)费用:300÷6×50=2500元;
方案(2)费用:150×128×15﹪=2880元;
方案(3)费用:132÷6×120=2640元;所以按工时结算最省钱。
25、(1)a-7;a+1;a+5 (2)这三个数是:10、17、24;
(3)框出的三个数的和不可能是64,因为,框出的三个数的和,是中间数的3倍,而64不是3的倍数。所以框出的三个数的和不可能是64。
26、设三位数的个位数字为x,则百位数字是(x+2),十位数字为a,
这个三位数是:100(x+2)+10a+x;交换百位数字与个位数字后三位数是:100x+10a+x+2,原三位数与新三位数的差是:198.与x的值无关。
所以满足条件得三位数按图示程序计算结果总能得到1089.
篇8:九年级数学上册期中测试卷及答案
九年级数学上册期中测试卷及答案
一.选择题(共12小题)
1.若=,则a的值为()
A.0B.±2C.±4D.2
2.关于x的方程ax2﹣3x+(a﹣2)=0是一元二次方程,则()
A.a>0B.a≠0C.a=0D.a≥0
3.已知:a=,b=,则的值是()
A.大于1B.小于1C.等于1D.无法确定
4.实数a在数轴上的对应点与原点的距离等于3,实数b满足b+7=0,则的值等于()
A.﹣或B.﹣6或6C.0D.6
5.已知△ABC的三边长分别为a,b,c,三角形面积S可以由海伦﹣秦九韶公式S=求得,其中p为三角形的半周长,即p=.若已知a=8,b=15,c=17,则△ABC的面积是()
A.120B.60C.68D.
6.下列根式中,不能再化简的二次根式是()
A.B.﹣C.D.
7.把一块长与宽之比为2:1的铁皮的四角各剪去一个边长为10厘米的小正方形,折起四边,可以做成一个无盖的盒子,如果这个盒子的容积是1500立方厘米,设铁皮的宽为x厘米,则正确的方程是()
A.(2x﹣20)(x﹣20)=1500B.10(2x﹣10)(x﹣10)=1500
C.10(2x﹣20)(x﹣20)=1500D.10(x﹣10)(x﹣20)=1500
8.对于一元二次方程ax2+bx+c=0(a≠0),有下列说法:
①当a<0,且b>a+c时,方程一定有实数根;
②若ac<0,则方程有两个不相等的实数根;
③若a﹣b+c=0,则方程一定有一个根为﹣1;
④若方程有两个不相等的实数根,则方程bx2+ax+c=0一定有两个不相等的实数根.
其中正确的有()
A.①②③B.①②④C.②③D.①②③④
9.华联超市四月份销售额为35万,预计第二季度销售总额为126万,设该超市五、六月份的销售额的平均增长率为x,则下面列出的方程中正确的是()
A.35(1+x)2=126B.35+35(2+x)2=126
C.35+35(1+x)+35(1+x2)=126D.35+35(1+x)+35(1+x)2=126
10.如图,正方形ABCD中,以BC为边向正方形内部作等边△BCE,连接AE并延长交CD于F,连接DE,下列结论:①AE=DE;②∠CEF=45°;③AE=EF;④△DEF∽△ABE,其中正确的结论共有()
A.1个B.2个C.3个D.4个
11.如图,点A,B为定点,定直线l∥AB,P是l上一动点.点M,N分别为PA,PB的中点,对于下列各值:①线段MN的长;②△PAB的周长;③△PMN的面积;④∠APB的大小.其中随点P的移动不会变化的是()
A.①②B.②④C.①③D.①④
12.如图,一个机器人从O点出发,向正东方向走3米到达A1点,再向正北方向走6米到达A2点,再向正西方向走9米到达A3点,再向正南方向走12米到达A4点,再向正东方向走15米到达A5点,按如此规律走下去,当机器人走到A6点时,则A6的坐标为()
A.(9,15)B.(6,15)C.(9,9)D.(9,12)
二.填空题(共6小题)
13.若b是a,c的比例中项,且a=cm,b=cm,则c=.
14.图形A与图形B位似,且位似比为1:2,图形B与图形C位似,且位似比为1:3,则图形A与图形C(填“一定”或“不一定”)位似.
15.若关于x的方程x2+(1﹣m)x+m+2=0的两个实数根之积等于m2﹣7m+2,则的值是.
16.将大圆形场地的半径缩小50m,得到小圆形场地的面积只有原场地的,则小圆形场地的半径为.
17.若等腰三角形的两边长分别是2,3,则这个三角形的周长是.
18.关于x的一元二次方程x2+mx+n=0有实数根,如果两根互为相反数,那么m=,如果两根互为倒数,那么n=.
三.解答题(共8小题)
19.(1)计算:|﹣3|+(π﹣3)0﹣÷+4×2﹣1.
(2)先化简,再求值:(x+1)(x﹣1)+x2(x﹣1),其中x=﹣2.
20.(1)化简:(a﹣)÷
(2)解方程:x(x﹣3)+x﹣3=0.
21.求证:不论m取何值,关于x的方程2x2+3(m﹣1)x+m2﹣4m﹣7=0总有两个不相等的实数根.
22.在平面直角坐标系中,△ABC的三个顶点坐标分别为A(2,﹣4),B(3,﹣2),C(6,﹣3).
(1)画出△ABC关于x轴对称的△A1B1C1;
(2)以O点为位似中心,在网格中画出△A1B1C1的位似图形△A2B2C2,使△A2B2C2与△A1B1C1的相似比为2:1.
23.如图,AD是△ABC的平分线,E为BC的中点,EF∥AB交AD于点F,CF的延长线交AB于点G,求证:AG=AC.
24.如图,在平面直角坐标系,A(a,0),B(b,0),C(﹣1,2),且|2a+b+1|+(a+2b﹣4)2=0.
(1)求a,b的值;
(2)在x轴的正半轴上存在一点M,使S△COM=S△ABC,求出点M的坐标.
25.某品牌饼干,如果每盒盈利10元,每天可售出500盒,经市场调查发现,在进价不变的情况下,若每盒涨1元,日销售量将减少20盒.现经销商要保证每天盈利6000元,同时又要使顾客得到实惠,那么每盒应涨价多少元?
26.如图所示:△ABC中,CA=CB,点D为AB上一点,∠A=∠PDQ=α.
(1)如图1,若点P、Q分别在AC、BC上,AD=BD,问:DP与DQ有何数量关系?证明你的结论;
(2)如图2,若点P在AC的延长线上,点Q在BC上,AD=BD,则DP与DQ有何数量关系?如图3,若点P、Q分别在AC、CB的延长线上,AD=BD,则DP与DQ有何数量关系?请在图2或图3中任选一个进行证明;
(3)如图4,若,作∠PDQ=2a,使点P在AC上,点Q在BC的延长线上,完成图4,判断DP与DQ的数量关系,证明你的结论.
参考答案
一.选择题(共12小题)
1.【解答】解:∵=,
∴4﹣a2≥0且a2﹣4≥0,
∴4﹣a2=0,
解得:a=±2.
故选:B.
2.【解答】解:关于x的方程ax2﹣3x+(a﹣2)=0是一元二次方程,得a≠0,
故选:B.
3.【解答】解:把a=,b=代入得:
==,
∵2006×2008=(2007﹣1)(2007+1)=20072﹣1,
∵2006×2008<20072,因此原式<1.
故本题选B.
4.【解答】解:∵a2=9,b=﹣7,
∴===0,
故选C.
5.【解答】解:由题意可得:p==20,
故S=
=60.
故选:B.
6.【解答】解:A、被开方数不含分母;被开方数不含能开得尽方的因数或因式,故A正确;
B、被开方数含分母,故B错误;
C、被开方数含能开得尽方的因数或因式,故C错误;
D、被开方数含能开得尽方的因数或因式,故D错误;
故选:A.
7.【解答】解:设铁皮的宽为x厘米,
那么铁皮的长为2x厘米,
依题意得10(2x﹣20)(x﹣20)=1500.
故选C.
8.【解答】解:①由a<0,且b>a+c,得出(a+c)2
②若ac<0,a、c异号,则△=b2﹣4ac>0,方程ax2+bx+c=0一定有实数根,所以②正确;
③若a﹣b+c=0,b=a+c,△=b2﹣4ac=(a+c)2﹣4ac=(a﹣c)2≥0,则一元二次方程ax2+bx+c=0有两个实数根,所以③错误;
④若方程ax2+bx+c=0有两个不相等的实数根,c可能为0,则方程bx2+ax+c=0,a2﹣4bc>0一定有两个不相等的实数根,所以④正确.
故选:B.
9.【解答】解:由题意可得:35+35(1+x)+35(1+x)2=126.
故选:D.
10.【解答】解:∵四边形ABCD是正方形,
∴AB=BC=CD=AD,∠DAB=∠ABC=∠BCD=∠ADC=90°,
∵△EBC是等边三角形,
∴BC=BE=CE,∠EBC=∠EBC=∠ECB=60°,
∴∠ABE=∠ECF=30°,
∵BA=BE,EC=CD,
∴∠BAE=∠BEA=∠CED=∠CDE=(180°﹣30°)=75°,
∴∠EAD=∠EDA=15°,
∴EA=ED,故①正确,
∴∠DEF=∠EAD+∠ADE=30°,
∴∠CEF=∠CED﹣∠DEF=45°,故②正确,
∵∠EDF=∠AFD=75°,
∴ED=EF,
∴AE=EF,故③正确,
∵∠BAE=∠BEA=∠EDF=∠EFD=75°,
∴△DEF∽△ABE,故④正确,
故选D.
11.【解答】解:∵A、B为定点,
∴AB长为定值,
∵点M,N分别为PA,PB的中点,
∴MN=AB为定值,∴①正确;
∵点A,B为定点,定直线l∥AB,
∴P到AB的距离为定值,
∴③正确;
当P点移动时,PA+PB的长发生变化,∴△PAB的周长发生变化,∴②错误;
当P点移动时,∠APB发生变化,∴④错误;
故选C.
12.【解答】解:由题意可知:OA1=3;A1A2=3×2;A2A3=3×3;可得规律:An﹣1An=3n,
当机器人走到A6点时,A5A6=18米,点A6的坐标是(9,12).
故选D.
二.填空题(共6小题)
13.【解答】解:根据比例中项的概念结合比例的基本性质,得:比例中项的平方等于两条线段的乘积,
所以b2=ac,即()2=c,c=2.
故答案为:2.
14.【解答】解:如图△ABC与△ADE位似,位似比为1:2,位似中心是A,
△ABC与△FGC位似,位似比为1:3,位似中心是C,
但△ADE与△FGC不位似,
故答案为:不一定.
15.【解答】解:根据题意得m+2=m2﹣7m+2,
整理得m2﹣8m=0,解得m1=0,m2=8,
当m=0时,方程化为x2+x+2=0,△=12﹣4×2<0,方程没有实数解,
所以m的值为8,
当m=8时,==4.
故答案为4.
16.【解答】解:设小圆的半径为xm,则大圆的半径为(x+50)m,
根据题意得:π(x+50)2=4πx2,
解得,x=50或x=﹣(不合题意,舍去).
故答案为:50m.
17.【解答】解:①若2为腰,满足构成三角形的条件,周长为2+2+3=4+3;
②若3为腰,满足构成三角形的条件,则周长为3+3+2=6+2.
故答案为:4+3或6+2.
18.【解答】解:∵一元二次方程x2+mx+n=0的两根互为相反数,
∴x1+x2=﹣m=0,
∴m=0;
∵一元二次方程x2+mx+n=0的两根互为倒数,
∴x1x2=n=1,
∴n=1,
故答案为:0,1.
三.解答题(共8小题)
19.【解答】解:(1)原式=3+1﹣+4×
=3+1﹣2+2
=4;
(2)原式=x2﹣1+x3﹣x2
=x3﹣1,
当x=﹣2时,原式=(﹣2)3﹣1=﹣9.
20.【解答】(1)解:原式=?=?=1﹣a;
(2)解:分解因式得:(x+1)(x﹣3)=0,
可得x+1=0或x﹣3=0,
解得:x1=﹣1,x2=3.
21.【解答】证明:∵△=b2﹣4ac
=[3(m﹣1)]2﹣4×2(m2﹣4m﹣7)
=m2+14m+65
=(m+7)2+16>0
∴不论m取何值时,方程总有两个不相等的实数根.
22.【解答】解:(1)如图,△A1B1C1为所作;
(2)如图,△A2B2C2为所作.
23.【解答】证明:∵E为BC的中点,EF∥AB,
∴==1,
∴F是CG的中点,即CF=GF,
如图,延长AF至P,使得PF=AF,
在△PFC和△AFG中,
,
∴△PFC≌△AFG(SAS),
∴AG=CP,∠GAF=∠P,
又∵AD是△ABC的平分线,
∴∠CAF=∠GAF,
∴∠P=∠CAF,
∴AC=CP,
∴AG=AC.
24.【解答】解:(1)∵|2a+b+1|+(a+2b﹣4)2=0,
∴,
解得:a=﹣2,b=3;
(2)由(1)知点A(﹣2,0),B(3,0),C(﹣1,2),
∴S△ABC=×AB×yC=×5×2=5,
设点M(x,0),
∵S△COM=S△ABC,
∴×x×2=×5,
解得:x=,
故点M的坐标为(,0).
25.【解答】解:设每盒应涨价x元,则现在的利润为(x+10)元,销量为(500﹣20x),由题意,得
(10+x)(500﹣20x)=6000.
解得:x1=5,x2=10.
∵要使顾客得到实惠,
∴x=5.
答:每每盒应涨价5元.
26.【解答】解:(1)分两种情况:
①当DP⊥AC,DQ⊥BC时,
∵∠A=∠B,∠APD=∠BQD=90°,AD=BD,
∴△ADP≌△BDQ,∴DP=DQ;
②当DP、AC不垂直,DQ、BC不垂直时;
如图1,过D作DM⊥AC于M,DN⊥BC于N,由①可得DM=DN;
在四边形CMDN中,∠DMC=∠DNC=90°,∴∠MDN+∠MCN=180°;
又∵∠MCN+2∠A=180°,∴∠MDN=∠PDQ=2∠A=2α;
∴∠PDM=∠QDN=2α﹣∠MDQ,
又∵∠DMP=∠DNQ=90°,DM=DN,
∴△DMP≌△DNQ,得DP=DQ;
综合上面两种情况,得:当点P、Q分别在AC、BC上,且AD=BD时,DP、DQ的数量关系为:相等.
(2)图2、图3的结论与图1的完全相同,证法一致;以图2为例进行说明:
图2中,过D作DM⊥AC于M,DN⊥BC于N,则DM=DN;
同(1)可得:∠MDN=∠PDQ=2α,则∠PDM=∠QDN=2α﹣∠PDN,
又∵∠DMP=∠DNQ=90°,DM=DN,
∴△DMP≌△DNQ,得DP=DQ;
图3的证法同上;
所以在图2、图3中,(1)的结论依然成立,即DP、DQ的数量关系为:相等.
(3)DP、DQ的数量关系为:DP=nDQ,理由如下:
如图4,过D作DM⊥AC于M,DN⊥BC于N;
∵∠A=∠B,∠AMD=∠BND=90°,
∴△ADM∽△BDN,
∴,即AD=nBD;
同上可得:∠MDN=∠PDQ=2∠A=2α;
∴∠MDP=∠NDQ=2α+∠NDP,
又∵∠DMP=∠DNQ=90°,
∴△DMP∽△DNQ,得:,即DP=nDQ;
所以在(3)题的条件下,DP、DQ的数量关系为:DP=nDQ.
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