上海市2016青浦区初三数学一模试卷(含答案)

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静安区2015学年第一学期期末教学质量调研九年级数学试卷 2016.1(完成时间:100分钟 满分:150分 )考生注意:1.本试卷含三个大题,共25题.答题时,考生务必按答题要求在答题纸规定的位置上作答,在草稿纸、本试卷上答题一律无效.2.除第一、二大题外,其余各题如无特别说明,都必须在答题纸的相应位置上写出证明或计算的主要步骤.一、选择题:(本大题共6题,每题4分,满分24分) 1.21的相反数是(A )2; (B )2-; (C )22; (D )22-. 2.下列方程中,有实数解的是(A )012=+-x x ; (B )x x -=-12; (C )012=--x x x ; (D )112=--xx x.3.化简11)1(---x 的结果是 (A )x x-1; (B )1-x x ; (C )1-x ; (D )x -1. 4.如果点A (2,m )在抛物线2x y =上,将此抛物线向右平移3个单位后,点A 同时平移到点A ’ ,那么A ’坐标为(A )(2,1); (B )(2,7) (C )(5,4); (D )(-1,4). 5.在Rt △ABC 中,∠C =90°,CD 是高,如果AD =m ,∠A =α, 那么BC 的长为 (A )ααcos tan ⋅⋅m ; (B )ααcos cot ⋅⋅m ; (C )ααcos tan ⋅m ; (D )ααsin tan ⋅m .6.如图,在△ABC 与△ADE 中,∠BAC =∠D ,要使△ABC 与△ADE 相似,还需满足下列条件中的 (A )AEABAD AC =; (B )DE BC AD AC =; (C )DE AB AD AC =; (D )AEBCAD AC =. 二、填空题:(本大题共12题,每题4分,满分48分) 7.计算:=-32)2(a ▲ . 8.函数23)(+-=x x x f 的定义域为 ▲ . 9.方程15-=+x x 的根为 ▲ .E10.如果函数m x m y -+-=1)3(的图像经过第二、三、四象限,那么常数m 的取值范围为 ▲ .11.二次函数162+-=x x y 的图像的顶点坐标是 ▲ .12.如果抛物线522+-=ax ax y 与y 轴交于点A ,那么点A 关于此抛物线对称轴的对称点坐标是 ▲ .13.如图,已知D 、E 分别是△ABC 的边AB 和AC 上的点,DE //BC ,BE 与CD 相交于点F ,如果AE =1,CE =2,那么EF ∶BF 等于 ▲ .14.在Rt △ABC 中,∠C =90°,点G 是重心,如果31sin =A ,BC =2,那么GC 的长等于 ▲ .15.已知在梯形ABCD 中,AD //BC ,BC =2AD ,设a AB =,b BC =,那么=CD ▲ .(用向量a 、b 的式子表示);16.在△ABC 中,点D 、E 分别在边AB 、AC 上,∠AED =∠B ,AB =6,BC =5,AC =4,如果四边形DBCE 的周长为225,那么AD17.如图,在□ABCD 中,AE ⊥BC ,垂足为E ,如果AB BC =8,54sin =B .那么=∠CDE tan ▲ .18. 将□ABCD (如图)绕点A 旋转后,点D 落在边AB 上的点D ’,点C 落到C ’,且点C ’、B 、C 在一直线上,如果AB =13,AD =3,那么∠A 的余弦值为 ▲ .三、解答题:(本大题共7题,满分78分)19.(本题满分10分)化简:xx x x x x x 296462222-+-÷---,并求当213=x 时的值.20.(本题满分10分)用配方法解方程:03322=--x x .21.(本题满分10分, 其中第(1)小题6分,第(2)小题4分))(第17题图)BA CED (第13题图)F(第18题图)D ABC如图,直线x y 34=与反比例函数的图像交于点A (3,a ),第一象限内的点B 在这个反比 例函数图像上,OB 与x 轴正半轴的夹角为α,且31tan =α.(1)求点B 的坐标; (2)求△OAB 的面积.22.(本题满分10分)如图,从地面上的点A 看一山坡上的电线杆PQ ,测得杆顶端点P 的仰角是26.6°,向前 走30米到达B 点,测得杆顶端点P 和杆底端点Q 的仰角分别是45°和33.7°.求该电线杆PQ 的高度(结果精确到1米).(备用数据:00.26.26cot ,50.06.26tan ,89.06.26cos ,45.06.26sin =︒=︒=︒=︒,50.17.33cot ,67.07.33tan ,83.07.33cos ,55.07.33sin =︒=︒=︒=︒.)23.(本题满分12分,其中每小题6分)已知:如图,在△ABC 中,点D 、E 分别在边BC 、AB 上,BD =AD =AC ,AD 与CE 相交 于点F ,EC EF AE ⋅=2.(1) 求证:∠ADC =∠DCE +∠EAF ;(2) 求证:AF ·AD=AB ·EF . 24.(本题满分12分,其中每小题6分)如图,直线121+=x y 与x 轴、y 轴分别相交于点A 、B ,二次函数的图像与y 轴相交于点C ,与直线121+=x y 相交于点A 、D ,CD //x 轴,∠CDA =∠OCA . (1) 求点C 的坐标;ADBF E(第23题图)(第21题图)BQP (第22题图)(2) 求这个二次函数的解析式.25.(本题满分14分,其中第(1)小题4分,第(2)、(3)小题各5分)已知:在梯形ABCD 中,AD //BC ,AC =BC =10,54cos =∠ACB ,点E 在对角线AC 上,且CE =AD ,BE 的延长线与射线AD 、射线CD 分别相交于点F 、G .设AD =x ,△AEF 的面积为y .(1)求证:∠DCA =∠EBC ;(2)如图,当点G 在线段CD 上时,求y 关于x 的函数解析式,并写出它的定义域; (3)如果△DFG 是直角三角形,求△AEF 的面积.静安区2015学年第一学期期末教学质量调研 九年级数学试卷参考答案及评分说明2016.1一、选择题:1.D ; 2.D ; 3.A ; 4.C ; 5.C ; 6.C . 二、填空题:7.68a -; 8.2-≠x ; 9.4=x ; 10.31<<m ; 11.(3, -8); 12.(2, 5); 13.31; 14.2; 15.b a 21--; 16.2; 17.21; 18.135. 三、解答题:19.解:原式= )2()3()2)(2()3)(2(2--÷-+-+x x x x x x x ············································································(4分)=2)3()2()2)(2()3)(2(--⋅-+-+x x x x x x x ················································································(1分)(第24题图)A BCD F GE(第25题图)=3-x x. ········································································································(2分) 当3321==x 时,原式=231311333+-=-=-. ·································(3分)20.解:023232=--x x , ·····································································································(1分) 23232=-x x ,·············································································································(1分) 16923)43(2322+=+-x x , ·······················································································(2分) 1633)43(2=-x , ··········································································································(2分) 43343±=-x , ··········································································································(2分) 433231+=x ,433232-=x . ··············································································(2分)21.解:(1)∵直线x y 34=与反比例函数的图像交于点A (3,a ), ∴334⨯=a =4,∴点的坐标A (3,4). ······························································(1分) 设反比例函数解析式为xky =, ·············································································(1分)∴12,34==k k ,∴反比例函数解析式为xy 12=. ···········································(1分)过点B 作BH ⊥x 轴,垂足为H , 由31tan ==OB BH α,设BH =m ,则OB =m 3,∴B (m 3,m ) ························(1分) ∴mm 312=,2±=m (负值舍去), ······································································(1分) ∴点B 的坐标为(6,2). ······················································································(1分)(1) ···································· 过点A作AE ⊥x 轴,垂足为E ,OBH AEHB OAE OAB S S S S ∆∆∆-+=梯形 ············································································(1分)=BH OH EH BH AE OE AE ⋅-⋅++⋅21)(2121 ················································(1分) ==⨯⨯-⨯++⨯⨯26213)24(2143219. ······················································(2分)22.解:延长PQ 交直线AB 于点H ,由题意得.由题意,得PH ⊥AB ,AB =30,∠PAH =26 .6°,∠PBH =45°,∠Q BH =33.7°, 在Rt △QBH 中,50.1cot ==∠QHBHQBH ,设QH =x ,BH =x 5.1, ·····················(2分) 在Rt △PBH 中,∵∠PBH =45°,∴PH = BH =x 5.1, ···············································(2分) 在Rt △PAH 中,00.2cot ==∠PHAHPAH ,AH =2PH =x 3, ···································(2分) ∵AH –BH =AB ,∴305.13=-x x ,20=x . ·························································(2分) ∴PQ =PH –QH =105.05.1==-x x x . ·····································································(1分) 答:该电线杆PQ 的高度为10米. ·················································································(1分)23.证明:(1)∵EC EF AE ⋅=2,∴AEECEF AE =. ··························································(1分) 又∵∠AEF =∠CEA ,∴△AEF ∽△CEA . ·······················································(2分) ∴∠EAF =∠ECA , ····························································································(1分) ∵AD =AC ,∴∠ADC =∠ACD , ·······································································(1分) ∵∠ACD =∠DCE +∠ECA =∠DCE +∠EAF . ·····················································(1分)(2)∵△AEF ∽△CEA ,∴∠AEC =∠ACB . ·······························································(1分)∵DA =DB ,∴∠EAF =∠B . ················································································(1分) ∴△EAF ∽△CBA . ·····························································································(1分)∴ACEFBA AF =. ···································································································(1分) ∵AC =AD ,∴ADEFBA AF =. ················································································(1分) ∴EF AB AD AF ⋅=⋅. ····················································································(1分)24.解:(1)∵直线121+=x y 与x 轴、y 轴分别相交于点A 、B , ∴A (–2,0)、B (0,1).∴OA =2,OB =1. ······················································(2分) ∵CD //x 轴,∴∠OAB =∠CDA ,∵∠CDA =∠OCA ,∴∠OAB =∠OCA . ··············(1分) ∴tan ∠OAB =tan ∠OCA , ·························································································(1分)∴OCOA OA OB =,∴OC 221=, ··················································································(1分) ∴4=OC ,∴点C 的坐标为(0,4). ································································(1分)(2)∵CD //x 轴,∴BOBCAO CD =.··················································································(1分)∵BC =OC –OB=4–1=3,∴132=CD ,∴CD =6,∴点D (6,4). ·························(1分) 设二次函数的解析式为42++=bx ax y , ····························································(1分)⎩⎨⎧++=+-=,46364,4240b a b a ………………(1分) ⎪⎩⎪⎨⎧=-=.23,41b a ·········································(1分) ∴这个二次函数的解析式是423412++-=x x y . ··················································(1分)25.解:(1)∵AD ∥BC ,∴∠DAC =∠ECB . ········································································(1分)又∵AD =CE ,AC =CB ,∴△DAC ≌△ECB . ······························································(2分) ∴∠DCA =∠EBC . ···································································································(1分) (2)过点E 作EH ⊥BC ,垂足为H .AE =AC –CE =x -10.x ACB CE CH 54cos =∠⋅=,∴EH =x 53. ····························································(1分) x x EH BC S CBE353102121=⨯⨯=⋅=∆. ································································(1分) ∵AF//BC .∴△AEF ∽△CEB ,∴2)(CEAE S S CEB AEF =∆, ·············································(1分) ∴22)10(3x x x y -=,∴x x x y 3006032+-=. ······················································(1分) 定义域为5550-≤<x . ·····················································································(1分) (3)由于∠DFC =∠EBC <∠ABC , 所以∠DFC 不可能为直角.(i )当∠DGF =90°时,∠EGC =90°,由∠GCE =∠GBC ,可得△GCE ∽△GBC .∴10tan xCB CE GB CG GBC ===∠. ·····································································(1分) 在Rt △EHB 中, x x xxBH EH GBC 4503541053tan -=-==∠. ···························(1分)∴xxx 450310-=,解得),(0舍去=x 或5=x . ∴155300560532=+⨯-⨯=∆AEF S . ·····························································(1分) (ii )当∠GDF =90°时,∠BCG =90°,由△GCE ∽△GBC ,可得∠GEC =90°,∠CEB =90°, ·····································································(1分)可得BE =6,CE =8,AE =2,EF =23,23=∆AEF S . ············································(1分) 综上所述,如果△DFG 是直角三角形,△AEF 的面积为15或23.。