2016年静安区九年级数学一模试卷

2016年静安区九年级数学一模试卷
2016年静安区九年级数学一模试卷

静安区2015学年第一学期九年级期末学业质量调研测试

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.

2

1的相反数是

(A )2; (B )2-; (C )22; (D )2

2

-. 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=--x

x 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 )

α

αcos tan ?m ; (D )αα

sin 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 )

AE

AB

AD AC =; (B )DE BC AD AC =

; (C )DE AB AD AC =; (D )AE

BC

AD AC =

. (第6题图)

E

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2

3

)(+-=

x x x f 的定义域为 ▲ . 9.方程15-=+x x 的根为 ▲ .

10.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

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31

sin =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10,那么AD 17.如图,在□ABCD 中,AE ⊥BC ,垂足为E ,如果BC =8,5

4

sin =

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,A

D =3,那么∠A 的余弦值为 ▲ .

(第17题图)

B

A C

E

D (第13题图)

F

(第18题图)

D A

B

C

三、解答题:(本大题共7题,满分78分) 19.(本题满分10分)

化简:x

x x x x x x 29

6462

222-+-÷---,并求当21

3=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))

如图,直线x y 3

4

=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3

1

tan =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 =?=?=?=?.)

(第21题图)

A

B

Q

P (第22题图)

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12

1

+=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12

1

+=

x y 相交于点A 、D ,CD //x 轴,∠CDA =∠OCA . (1) 求点C 的坐标; (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

已知:在梯形ABCD 中,AD //BC ,AC =BC =10,5

4

cos =

∠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.

A

D

B

F E

(第23题图)

A B C

D F G

E (第25题图)

静安区2015学年第一学期期末学业质量调研 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 -; 82x ≠-.; 9.4=x ; 10.13m <<; 11.(3, -8); 12.(2, 5); 13.

31; 14.2; 15.b a 2

1--; 16.4或无解; 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) =

3

-x x

. ·············································································· (2分) 当332

1==x

时,原式=

2

3

13

113

33+-

=-=

-. ························ (3分) 20.解:2

33

022x x -

-=, ·································································· (1分) 23322x x -=, ········································································ (1分)

223339()24216x x -+=+, ························································ (2分)

2333()416

x -=, ······································································ (2分)

34x -

=·················································································· (2分)

1x =

2x = ······························································· (2分)

21.解:(1)∵直线x y 3

4

=

与反比例函数的图像交于点A (3,a )

, ∴33

4

?=

a =4,∴点的坐标A (3,4)

. ·············································· (1分) 设反比例函数解析式为x

k

y =, ·························································· (1分)

∴12,34==k k ,∴反比例函数解析式为x

y 12=. ································ (1分)

过点B 作BH ⊥x 轴,垂足为H , 由3

1

tan ==OB BH α,设BH =m ,则OB =m 3,∴B (m 3,m ) ·

··············· (1分) ∴m

m 312

=

,2±=m (负值舍去), ···················································· (1分) ∴点B 的坐标为(6,2). ································································ (1分)

(2)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) ==??+?++??262

1

3)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,∠P AH =26 .6°,∠PBH =45°,∠Q BH =33.7°, 在Rt △QBH 中,50.1cot ==

∠QH

BH

QBH ,设QH =x ,BH =x 5.1, ············· (2分) 在Rt △PBH 中,∵∠PBH =45°,∴PH = BH =x 5.1, ······························· (2分) 在Rt △P AH 中,00.2cot ==

∠PH

AH

PAH ,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,∴

AE

EC

EF 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)

AC

EF

BA AF =

. ·········································································· (1分) ∵AC =AD ,∴AD

EF

BA AF =

. ··························································· (1分) ∴EF AB AD AF ?=?. ······························································· (1分)

24.解:(1)∵直线12

1

+=

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) ∴

OC

OA OA OB =

,∴OC 2

21=, ······························································ (1分) ∴4=OC ,∴点C 的坐标为(0,4). ················································ (1分) (2)∵CD //x 轴,∴

BO

BC

AO CD =

. ····························································· (1分) ∵BC =OC –OB=4–1=3,∴1

3

2=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42

3

41

2++-=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 5

3

. ·

··········································· (1分) x x EH BC S CBE

35

3

102121=??=?=?.

················································ (1分) ∵AF//BC .∴△AEF ∽△CEB ,∴

2

)(CE

AE S S CEB AEF =?, ······························· (1分) ∴2

2

)10(3x x x y -=,∴x x x y 3006032+-=. ········································ (1分)

定义域为05x <≤. ······························································· (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 .

∴10

tan x

CB CE GB CG GBC ===

∠.

···················································· (1分) 在Rt △EHB 中, x x x

x

BH EH GBC 45035

1053tan -=-==∠. ·················· (1分)

x

x

x 450310-=

,解得),(0舍去=x 或5=x . ∴155

300

560532=+?-?=?AEF S . ·············································· (1分)

(ii )当∠GDF =90°时,∠BCG =90°,

可得∠GEC =90°,∠CEB =90°, ················································· (1分)

可得BE =6,CE =8,AE =2,EF =

23,2

3

=?AEF S . ······························ (1分) 综上所述,如果△DFG 是直角三角形,△AEF 的面积为15或2

3

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