
第Ⅰ卷
一、選擇題(本大題共6個小題,每小題3分,共18分.在每個小題給出的四個選項中,只有一項符合題目要求,請選出并在答題卡上將該項涂黑)
第Ⅱ卷
二、填空題(本大題共10小題,每小題3分,共30分)
7.x≥-12且x≠18.4.3×10﹣89.2510.①②③
11.x<﹣1或x>312.3213.8π514.7
15.3516.(65,125)
三、解答題(本大題共10個小題,共102分.解答應(yīng)寫出文字說明,證明過程或演算步驟)
17.(10分)
解:(1)原式=x2﹣1﹣(x2+2x+1)
=x2﹣1﹣x2﹣2x﹣1
=﹣2x﹣2;··········································································5分
(2)去分母得:2x=3x﹣3x+3,
解得:x=32,
檢驗:把x=32代入得:3(x﹣1)≠0,
∴x=32是分式方程的解.································································10分
18.(8分)
解:(1)如圖,△EFG即為所求(答案不唯一);···········································4分
(2)如圖,菱形MNPQ即為所求(答案不唯一).··········································8分
19.(8分)
解:(1)該書店4月份的營業(yè)總額是:182﹣(30+40+25+42)=45(萬元),
補全統(tǒng)計圖如下:
·················································2分
(2)42×25%=10.5(萬元),
答:5月份“黨史”類書籍的營業(yè)額是10.5萬元;··········································4分
(3)4月份“黨史”類書籍的營業(yè)額是45×20%=9(萬元),
∵10.5>9,且1﹣3月份的營業(yè)總額以及“黨史”類書籍的營業(yè)額占當月營業(yè)額的百分比都低于4、5月份,
∴5月份“黨史”類書籍的營業(yè)額最高.··················································8分
20.(8分)
解:(1)由題意知,七年級推薦了1名女生,八年級推薦了2名女生,
∴從推薦的女生中隨機選一人,來自七年級的概率是13.
故答案為:13.·······································································4分
(2)列表如下:
共有9種等可能的結(jié)果,其中恰好是一男一女的結(jié)果有5種,
∴恰好是一男一女的概率為59.·······················································8分
21.(10分)
解:(1)∵y=﹣x2+2ax﹣a2﹣a+2=﹣(x﹣a)2﹣a+2,
∴拋物線y=﹣x2+2ax﹣a2﹣a+2的頂點為(a,﹣a+2),
∵拋物線的頂點在第二象限,
∴a<0-a+2>0,
解得a<0;········································································3分
(2)∵拋物線y=﹣x2+2ax﹣a2﹣a+2的頂點在反比例函數(shù)y=-8x(x<0)的圖象上,
∴a(﹣a+2)=﹣8,
解得a=4或a=﹣2,
∵a<0,
∴a=﹣2,
∴頂點為(﹣2,4),
∵y1=y(tǒng)2,
∴點A(x1,y1),B(x2,y2)關(guān)于直線x=﹣2對稱,
∴x1+x22=-2,
∴x1+x2=﹣4;········································································6分
(3)∵當1<x1<x2時,都有y2<y1<1,
∴a<1-1+2a-a2-a+2≤1或a=1-a+2=-1+2a-a2-a+2,
解得a≤0或a=1,
故a的取值范圍為a≤0或a=1.·······················································10分
22.(10分)
解:如圖,延長AE交CD延長線于點M,過點A作AN⊥BC于點N,則四邊形AMCN是矩形,
∴NC=AM,AN=MC,
在Rt△EMD中,∠EDM=37°,
∵sin∠EDM=EMED,cs∠EDM=DMED,
∴EM=ED×sin37°≈20×0.6=12(米),
DM=ED×cs37°≈20×0.8=16(米),
∴AN=MC=CD+DM=74+16=90(米).·················································5分
由題意,在Rt△ANB中,∠BAN=42°,
∵tan∠BAN=BNAN,
∴BN=AN×tan42°≈90×0.9=81(米),
∴BC=BN+AE+EM=81+3+12=96(米),
答:大樓BC的高度約為96米.·························································10分
23.(10分)
解:(1)結(jié)論:四邊形CEGF是菱形.
理由:∵四邊形ABCD是矩形,
∴AD∥BC,
∴∠GFE=∠FEC,
∵圖形翻折后點G與點C重合,EF為折痕,
∴∠GEF=∠FEC,F(xiàn)G=FC,EG=GC,
∴∠GFE=∠FEG,
∴GF=GE,
∴GE=EC=CF=FG,
∴四邊形CEGF為菱形;·································································5分
(2)如圖2,當G與A重合時,CE的值最大,由折疊的性質(zhì)得AE=CE,
∵∠B=90°,
∴Rt△CDF中,CD2=DF2+CF2,
即x2=22+(16﹣x)2,
解得,x=638,
∴DF=638.···········································································10分
24.(12分)
解:(1)設(shè)y與x的函數(shù)解析式為y=kx+b,
將(10,30)、(16,24)代入,得:10k+b=3016k+b=24,
解得:k=-1b=40,
所以y與x的函數(shù)解析式為y=﹣x+40(10≤x≤16);········································3分
(2)根據(jù)題意知W=(x﹣10)y
=(x﹣10)(﹣x+40)
=﹣x2+50x﹣400
=﹣(x﹣25)2+225,
∵a=﹣1<0,
∴當x<25時,W隨x的增大而增大,
∵10≤x≤16,
∴當x=16時,W取得最大值,最大值為144;············································7分
(3)根據(jù)題意知,﹣(x﹣25)2+225=104,
∴x=14或x=36(舍去),
答:銷售單價為14元.·································································12分
25.(12分)
解:(1)反比例函數(shù)y1=kx與正比例函數(shù)y2=mx的圖象都是中心對稱圖形,
∵A(k,1),
∴點B的坐標為(﹣k,﹣1);
故答案為:(﹣k,﹣1);······························································2分
(2)解:∵點C為反比例函數(shù)y1=kx圖象上一點,點C的橫坐標為4k,
∴C(4k,14),
設(shè)直線BC的解析式為y=mx+n(m≠0),
∴14=4km+n-1=-km+n,
∴m=14kn=-34,
∴直線BC的解析式為y=14kx-34,······················································5分
作AN∥y軸交BC于點N,則N(k,-12),
∴AN=1+12=32,
∴S△ABC=12AN×(xC-xB)=12×32×(4k+k)=5,
解得k=43;·········································································7分
(3)由題意得P(5k,15),而B(﹣k,﹣1),
同理求得直線BP的解析式為y=15kx-45,
∵A(k,1),
∴D(k,-35),E(5k,-35),
∵四邊形ADEF是正方形,
∴AD=DE,即1+35=5k-k,
解得k=25.·········································································12分
26.(14分)
(1)證明:∵∠A=∠D,∠B=∠C,
∴△ACE∽△DBE·····································································2分
(2)①∵∠CBA=∠D,∠B=∠C,
∴∠CAB+∠C=90°,
∴CD⊥AB,
又∵CD過圓心,
∴AE=BE=1,
在Rt△AEC中,tan∠CAE=CEAE=3,
∴CE=3,············································································5分
設(shè)OE=x,則OC=3﹣x=OB,
在Rt△OEB中,由勾股定理得:OB2=OE2+BE2,
即(3﹣x)2=x2+1,
解得:x=43,
∵OG=OB,AE=BE,
∴OE是△AGB的中位線,
∴AG=2OE=83;·····································································8分
②∵BG是⊙O的直徑,
∴∠BAG=90°,
∵∠BAG=∠BEO=90°,
∴OC∥AG,
∴△GAF∽△OCF,
∴FGOF=AGOC,
設(shè)AE=t,在Rt△ACE中,tan∠CAE=CEAE=x,
∴CE=tx
設(shè)OE=d,則OC=tx﹣d=OB,
在Rt△OEB中,由勾股定理得:OB2=OE2+BE2,
即(tx﹣d)2=d2+t2,
解得:d=t2x2-t22tx,OC=tx-d=t2x2+t22tx,
∴OFFG=OCAG=OC2d=x2+12x2-2,
∴y=2x2x2-1.·········································································14分1
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