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苏科版数学九年级上册期末模拟试卷一、选择题1.一元二次方程x2=1的解是()A.x=1B.x=-1C.x1=1,x2=-1D.x=02.⊙O的半径为1,同一平面内,若点P与圆心O的距离为1,则点P与⊙O的位置关系是()A.点P在⊙O外B.点P在⊙O上C.点P在⊙O内D.无法确定3.9名同学参加
歌咏比赛,他们的预赛成绩各不相同,现取其中前4名参加决赛,小红同学在知道自己成绩的情况下,要判断自己能否进入决赛,还需要知道这9名同学成绩的()A.中位数B.极差C.平均数D.方差4.已知二次函数y=ax2+bx+c中,函数y与自变量x的部分对应值
如表,则方程ax2+bx+c=0的一个解的范围是()x6.176.186.196.20y-0.03-0.010.020.04A.-0.01<x<0.02B.6.17<x<6.18C.6.18<x<6.19D.6.19<x<6.205.若点A(
-1,a),B(2,b),C(3,c)在抛物线y=x2上,则下列结论正确的是()A.a<c<bB.b<a<cC.c<b<aD.a<b<c6.如图,点E在y轴上,⊙E与x轴交于点A、B,与y轴交于点C、D,若C(0,9
),D(0,-1),则线段AB的长度为()A.3B.4C.6D.8二、填空题7.若ba=3,则b+aa=.8.一组数据:2,3,-1,5的极差为.9.一元二次方程x2-4x+1=0的两根是x1,x2,则x1•x2的值是.10.某产品原来每件成本是100元,连续两次
降低成本后,现在成本是81元,设平均每次降低成本的百分率为x,可得方程.11.在平面直角坐标系中,将抛物线y=2x2先向右平移3个单位,再向上平移1个单位,得到的抛物线的函数表达式为.ByABEDxOC(第6题)12.已知圆锥的
底面半径为6cm,母线长为8cm,它的侧面积为cm2.13.如图,根据所给信息,可知BCB′C′的值为.14.已知二次函数y=ax2+bx+c中,函数y与自变量x的部分对应值如表,则当x=3时,y=.x„-3-2-101„y„73113„15.如图,AB是
⊙O的一条弦,C是⊙O上一动点且∠ACB=45°,E、F分别是AC、BC的中点,直线EF与⊙O交于点G、H.若⊙O的半径为2,则GE+FH的最大值为.16.如图,在矩形ABCD中,M、N分别是边AD、BC的中点,点P、Q在DC边上,且PQ
=14DC.若AB=16,BC=20,则图中阴影部分的面积是.三、解答题17.(1)解方程:(x+1)2=9;(2)解方程:x2-4x+2=0.18.已知关于x的一元二次方程(a+1)x2-x+a2-2a-2=0有一根是1,求a的值.(第13题)OOCBHFEGA(第15题)ABNC
QPDMO(第16题)19.射击队为从甲、乙两名运动员中选拔一人参加比赛,对他们进行了六次测试,测试成绩如下表(单位:环):第一次第二次第三次第四次第五次第六次平均成绩中位数甲108981099①乙107101098②9.5(1)完成表中填
空①;②;(2)请计算甲六次测试成绩的方差;(3)若乙六次测试成绩方差为43,你认为推荐谁参加比赛更合适,请说明理由.20.一只不透明的袋子中,装有三个分别标记为“1”、“2”、“3”的球,这三个球除了标记不同外,其余均
相同.搅匀后,从中摸出一个球,记录球上的标记后放回袋中并搅匀,再从中摸出一个球,再次记录球上的标记.(1)请列出上述实验中所记录球上标记的所有可能的结果;(2)求两次记录球上标记均为“1”的概率.21.如图,在半径为2的⊙O中,弦AB长为2.(1)求点O到AB的距离.(2
)若点C为⊙O上一点(不与点A,B重合),求∠BCA的度数;22.已知二次函数y=x2-2x-3.(1)该二次函数图象的对称轴为;(2)判断该函数与x轴交点的个数,并说明理由;(3)下列说法正确的是(填写所有正确说法的序号)①顶点坐标为(1,-4);②当y>0时,-1<x<3;③在同
一平面直角坐标系内,该函数图象与函数y=-x2+2x+3的图象关于x轴对称.23.如图,在四边形ABCD中,AC、BD相交于点F,点E在BD上,且ABAE=BCED=ACAD.(1)求证:∠BAE=∠CAD;(2)求证:△ABE∽△ACD.ABO(第21题)
ABCDFE(第23题)24.有这样一道例题:据此,一位同学提出问题:“用这根长22cm的铁丝能否围成面积最大的矩形?若能围成,求出面积最大值;若不能围成,请说明理由.”请你完成该同学提出的问题.25.如图,在△ABC中,AB=B
C,D是AC中点,BE平分∠ABD交AC于点E,点O是AB上一点,⊙O过B、E两点,交BD于点G,交AB于点F.(1)判断直线AC与⊙O的位置关系,并说明理由;(2)当BD=6,AB=10时,求⊙O的半径.ABFOEDGC(第25题)26.已知一次函数y=x+4的图象与二次函数
y=ax(x-2)的图象相交于A(-1,b)和B,点P是线段AB上的动点(不与A、B重合),过点P作PC⊥x轴,与二次函数y=ax(x-2)的图象交于点C.(1)求a、b的值(2)求线段PC长的最大值;(3)若△PAC为直角三角形,请直接写出点P的坐标.ABPCOxy(第26题)27.如图,折叠边
长为a的正方形ABCD,使点C落在边AB上的点M处(不与点A,B重合),点D落在点N处,折痕EF分别与边BC、AD交于点E、F,MN与边AD交于点G.证明:(1)△AGM∽△BME;(2)若M为AB中点,则AM3=AG4=MG5;(3)△AGM的
周长为2a.ABCDMNEFG(第27题)参考答案一、选择题(本大题共6小题,每小题2分,共12分)二、填空题(本大题共10小题,每小题2分,共20分)7.48.69.110.100(1-x)2=8111.y=2(x-3)2+112.48π13.1214.1315.4-216.92三
、解答题(本大题共11小题,共88分)17.(本题10分)(1)解:x+1=±3,∴x1=2,x2=-4.„„„„„„„„„„„„„„„„„„„„„5分(2)方法一:解:a=1,b=-4,c=2,b2-4a
c=8>0,x=4±222=2±2,„„„„„„„„„„„„„„„„3分∴x1=2+2,x2=2-2.„„„„„„„„„„„„„„5分方法二:解:x2-4x=-2,x2-4x+4=-2+4,(x-2)2=2,„„„„„„„„„„„„„„„„„„„„3分x-2=
±2,∴x1=2+2,x2=2-2.„„„„„„„„„„„„5分18.(本题6分)解:将x=1代入,得:(a+1)2-1+a2-2a-2=0,解得:a1=-1,a2=2.„„„„„„„„„„„„„„„„„„„5分∵a+1≠0,
∴a≠-1,∴a=2.„„„„„„„„„„„„„„„„„„„„„„„„„6分19.(本题8分)解:(1)9;9.„„„„„„„„„„„„„„„„„„„„„„„„2分题号123456答案CBACDC(2)S甲2=23.„„„„„„„„„„„„„„„„„„„„„„„„4分(3)
∵XX甲乙,S甲2<S乙2,∴推荐甲参加比赛合适.„„„„„„„„„„„„„„„„„„8分20.(本题7分)解:(1)列表如下:„„„„„„„„„„„„„„„„„„„„„„„„„„„„„4分(2)在这种情况下,共包含9种结
果,它们是等可能的.„„„„„„5分所有的结果中,满足“两次记录球上标记均为‘1’”(记为事件A)的结果只有一种,所以P(A)=19.„„„„„„„„„„„„„„„„„„„„7分21.(本题8分)解:(1)过点O作OD⊥
AB于点D,连接AO,BO.∵OD⊥AB且过圆心,AB=2,∴AD=12AB=1,∠ADO=90°.„„„„„„„„„„„„„„„2分在Rt△ADO中,∠ADO=90°,AO=2,AD=1,∴OD=AO2-AD2=3.即点O到AB的距离为3.„„„„4分(2)∵AO=BO=2,AB=2,∴△AB
O是等边三角形,∴∠AOB=60°.„„„„„„„„„„6分若点C在优弧⌒ACB上,则∠BCA=30°;若点C在劣弧⌒AB上,则∠BCA=12(360°-∠AOB)=150°.„„8分22.(本题8分)解:(1)直线x=1.„„„„„„„„„„„„„„„„„„2
分结果1231(1,1)(1,2)(1,3)2(2,1)(2,2)(2,3)3(3,1)(3,2)(3,3)(2)令y=0,得:x2-2x-3=0.∵b2-4ac=16>0,∴方程有两个不相等的实数根,
∴该函数与x轴有两个交点.„„„„„„„„„„„„„„„6分(3)①③.„„„„„„„„„„„„„„„„„„„„„„„„8分23.(本题8分)证明:(1)在△ABC与△AED中,∵ABAE=BCED=ACA
D,∴△ABC∽△AED.„„„„„„„„„„„„„„„„„„„„2分∴∠BAC=∠EAD,∴∠BAC-∠EAF=∠EAD-∠EAF,即∠BAE=∠CAD.„„„„„„„„„„„„„„„„„„„„4分(2)∵ABAE=ACAD,∴ABAC=AEAD
.„„„„„„„„„„„„„„„„„6分在△ABE与△ACD中,∵∠BAE=∠CAD,ABAC=AEAD,∴△ABE∽△ACD.„„„„„„„„„„„„„„„„„„„8分24.(本题7分)解:能围成.设当矩形的一边长为xcm时,面积
为ycm2.由题意得:y=x²(222-x)„„„„„„„„„„„„„„„„„„„„3分=-x2+11x=-(x-112)2+1214„„„„„„„„„„„„„„„„„5分∵(x-112)2≥0,∴-(x-112)2+1214≤1214.∴当x=112时,y有最大值,ymax=1214,此时222
-x=112.答:当矩形的各边长均为112cm时,围成的面积最大,最大面积是1214cm2.„7分25.(本题8分)解:(1)AC与⊙O相切.本题答案不惟一,下列解法供参考.证法一:∵BE平分∠ABD,∴∠OBE=∠DBO.∵OE=OB,∴∠OBE=∠
OEB,∴∠OBE=∠DBO,∴OE∥BD.„„„„„„„„„„„„„2分∵AB=BC,D是AC中点,∴BD⊥AC.∴∠ADB=90°.∵AC经过⊙O半径OE的外端点E,∴AC与⊙O相切.„„„4分证法二:
∵BE平分∠ABD,∴∠ABD=2∠ABE.又∵∠ADE=2∠ABE,∴∠ABD=∠ADE.∴OE∥BD.„„„2分∵AB=BC,D是AC中点,∴BD⊥AC.∴∠ADB=90°.∵AC经过⊙O半径OE的外
端点E,∴AC与⊙O相切.„„„4分(2)设⊙O半径为r,则AO=10-r.由(1)知,OE∥BD,∴△AOE∽△ABD.„„„„„„„„„„6分∴AOAB=OEBD,即10-r10=r6,„„„„„„„„„„„„„„„„„
„7分∴r=154.∴⊙O半径是154.„„„„„„„„„„„„„„„8分26.(本题9分)解:(1)∵A(-1,b)在直线y=x+4上,∴b=-1+4=3,∴A(-1,3).又∵A(-1,3)在抛物线y=ax(x-2)上,∴3=-a²(-1-2),解得:
a=1.„„„„„„„„„„„2分(2)设P(m,m+4),则C(m,m2-2m).∴PC=(m+4)-(m2-2m)=-m2+3m+4=-(m-32)2+254„„„„„„„„„„„„„„„„5分∵(m-32)2≥0,∴-(m-32)2+254≤254.∴当
m=32时,PC有最大值,最大值为254.„„„„„„„„„7分(3)P1(2,6),P2(3,7).„„„„„„„„„„„„„„„9分27.(本题9分)证明:(1)∵四边形ABCD是正方形,∴∠A=∠B=∠C=90°,∴∠AMG+
∠AGM=90°.∵EF为折痕,∴∠GME=∠C=90°,∴∠AMG+∠BME=90°,∴∠AGM=∠BME.„„„„„„„„„„„„„„„„„„„2分在△AGM与△BME中,∵∠A=∠B,∠AGM=∠BME,∴△AGM
∽△BME.„„„„„„„„„„„„„„„„„„„3分(2)∵M为AB中点,∴BM=AM=a2.设BE=x,则ME=CE=a-x.在Rt△BME中,∠B=90°,∴BM2+BE2=ME2,即(a2)2+x2=(a-x)2,∴x=38a,∴BE=
38a,ME=58a.由(1)知,△AGM∽△BME,∴AGBM=GMME=AMBE=43.∴AG=43BM=23a,GM=43ME=56a,∴AM3=AG4=MG5.„„„„„„„„„„„„„„„„„„
„„6分(3)设BM=x,则AM=a-x,ME=CE=a-BE.在Rt△BME中,∠B=90°,∴BM2+BE2=ME2,即x2+BE2=(a-BE)2,解得:BE=a2-x22a.由(1)知,△AGM∽△BME,∴C△AGMC△BME=AMBE=2aa+x.∵
C△BME=BM+BE+ME=BM+BE+CE=BM+BC=a+x,∴C△AGM=C△BME²AMBE=(a+x)²2aa+x=2a.„„„„„„„„„9分