1、 2018 北京市平谷区初三（上）期末 数 学 2018.1 1 2 3 2B 4 16 2 . 1 1 2 a b ab b A 3 2 B 2 3 C 1 2 D 1 2 2 AD BE CF 12 l ,l A,B,C D,E,F AB=1 BC=3 DE=2 EF A 4 B 5 C 6 D 8 3 2 1 yx A 0,0 B 1,1 C 0, 1 D 1,0 4 Rt ABC C=90 A=30 CD AB D CBD ABC A 3 2 B 3 3 C 1 4 D 1 25 Rt ABC C=90 AB=5 AC=3 sinB A 3 5 B 4 5 C 3 4 D 5 36 A
2、BC O OA OB ABO=40 C A 100 B 80 C 50 D 40 7 2 y x 11 A x ,y 22 B x ,y x1 x2 x1x2 0 y1 y2 A B C 0 D 8 A 1,1 B 1,1 C 1, 2 D 1, 2 A B C D A 2018 A 1,1 B 1,1 C 1, 2 D 1, 2 16 2 B O A C D C A B 9 2 23 y x x 2 y x h k h= k= 10 120 6cm cm 11 1,1 x 12 ABCD B=60 AB=2 ABCD 13 AB OB=1 OC AB D BC 14 x 2 21 y ax
3、ax a a 0 x 15 xOy DEF ABC ABC DEF 16 30 1 AD 2 AD O O A 3 O OA O AD B 4 B OB O C 5 AC DAC 30 68 17-23 5 24 6 25 6 26 27 7 28 8 . 17 1 1 2sin30 8 3 2 D C A B O D C O A B 18 2 y x bx c A B C 1 b c 2 19 ABC= BCD=90 A=45 D=30 BC=1 AC BD O BO DO 20 AB O CD AB E A AB=4 CD E D C A O B O D A B C 21 A B 700
4、B D 700 AB 16 BD 20 A 126 D 22 xOy y= k x k 0 x 0 y=2x 2 Q 2 m 1 m k 2 P a 0 a0 x P y y=2x 2 M y= k x N a=4 MN PM PN a 23 ABCD AC BD O O EO BD BA E AD F EF=OF CBD=30 BD=63 AF F E O A B C D 24 C AB O C O CD B BE CD E AB=6cm AC xcm B E ycm C A B y 0 D E C O B A y x 1 x y x/cm 0 1 2 3 4 5 6 y/cm 0 1 1.
5、9 2.6 3 m 0 m 2 3 2 1 2 yx BAC 25 Rt ABC ACB=90 AD BAC BC D O AB O O A D AB E 1 BC O 2 AC=2 AB=6 BE 26 2 2 y x mx D 1 D m E O D A B C 2 2 2 y x mx x 3 2 2 y x mx y=m m 27 Rt ABC BAC AB=AC D AD AD AB AD A 90 AE DE CE BD 1 1 2 BD CE 3 BD CE P ADE A EAC AB=2 AD=1 PB C A B D 1 C A B 28 -3 5 5 -3 1 O 5 2
6、 M,N M (m,n) (m n) P M,N M (4,0) P P 5 m n 数学试题答案 16 2 16 2 9 1 2 10 4 11 1 y x 12 23 13 2 2 13 1 2 3 22 14 ABC O 15 16 68 17-23 5 24 6 25 5 26 27 7 28 8 . 17 = 1 2 2 2 2 3 2 4 =6 2 2 5 18 1 A 1,0 B 0,3 1 0, 3 . bc c 2 2 3 b c 4 2 5 19 ABC= BCD AB CD 1 A= ACD 2 ABO CDO 3 BO AB CO CD 4 1 2 3 4 5 6 7
7、8 A C D D A C B B Rt ABC ABC A BC=1 AB=1 Rt BCD BCD D BC=1 CD= 3 13 3 3 BO CO 5 20 A COB 1 AB=4 OC=2 2 CD AB E CE= 1 2 CD 3 Rt OCE CEO COB OC=2 CE=1 4 CD=2 5 21 1 C E F H D B A G Rt ABC ACB AB=700 sin BC 2 BC=AB Rt BDE DBE BD=AB=700 sin DE 3 DE=BD EF=BC 4 FH=AG=126 DH 5 DH=DE+EF+FH 22 1 y=2x 2 Q 2 m
8、 m=2 1 Q 2 2 y= k x Q 2 2 k=4 2 2 a=4 P 4 0 y= 4 x 3 M 4,6 N 4,1 MN=5 4 PM PN a 2 5 23 AD BC OD= 1 2 BD=33 1 CBD ADB EO BD O DOF Rt ODF 3 3 OF OD OF=3 2 FD=6 O OG AB AD G AEF GOF AF EF GF OF EF=OF AF=GF O BD G AD 3 AF=GF=x AD=6+x AG= 6 2 x xx 4 x=2 AF=2 5 EF BC H ODF OHB OH=OF 3 AD BC EAF EBH EF AF
9、EH BH EF=OF G F E O A B C D H F E O A B C D 1 3 AF BH 4 BH=6 AF=2 24 1 m=2.76 1 2 4 3 5 BAC =30 6 25 1 OD OA=OD OAD= ODA AD BAC CAD= OAD CAD= ODA OD AC 1 ACB ODB 2 OD BC D BC O 3 2 OD AC BDO BCA OD BO AC BA 4 AC=2 AB=6 OD=r BO=6 r 6 26 rr r= 3 2 AE=3 BE=3 5 26 1 2 2 y x mx 2 2 x m m 1 D m, 2 m 2 2 y
10、=0 2 20 x mx 12 02 x ,x m x 0,0 , 2m,0 4 3 2 2 y x mx y=m D y=m 5 2 m m 6 2 mm 0 y= 2 mm m 1 m 0 7 2 2 y x mx y=m 2 2 x mx m 5 2 2 x mx =m 2 = 2 4 mm = 2 4 4 0 mm 12 0, 1 mm 6 m 1 m 0 7 27 1 1 E C A B D 2 BD CE BD=CE 2 DAB+ BAE= CAE+ BAE DAB= CAE 3 AD=AE AB=AC ABD ACE BD=CE 4 3 PB 25 5 65 5 7 P D E C A BP E D C A B28 1 4,3 3,4 2 2 MN OM=ON=4 Rt OMN O OA MN A M,N OA 3 P OA 4 P y=x 5 MN P m n=52 6 M,N M,N m n=0 7 m n 0 m n 52 8
