1、 2018 10 12 4 48 1 y= 2 x 3 2 +1 ( ) A 3 1 B 3 1 C 1 3 D 1 3 2 8 PO=6 P A P B P C P D 3 A B C A B C D 4 2 yx =- 1 3 A 2 ( 1) 3 = - + + yx B 2 ( 1) 3 yx = - + - C 2 ( 1) 3 = - - + yx D 2 ( 1) 3 yx = - - - 5 ABCDE A l BE ( ) A B C D 6 m x m y m 2 2 ) 2 ( A y B x C . x D x 7 A 4 B 3 C 2 D 1 8 y=2x 2 -4
2、x-5 A y= -2x 2 -4x-5 B y= -2x 2 +4x+5 C y=-2x 2 +4x-9 D 9 Rt ABC AB c BC a ACB A B C D 10 2 2 x x y 2 x y 3 1 2 x y 6 8 6 2 x x y y x A B D 11 C AB O AC BC AC BC ACDE BCFG DE FG AC BC M N P Q MP+NQ=14 AC+BC=18 AB A 92 B 90 7C 13 D 16 12 y=x 2 +bx+c x A m n B m 8 n n= A 12 B 14 C 16 D 18 6 4 24 13 y=
3、x 2 4x+5 y= x h 2 +k y= 14 ABCD O A C C 15 OAB A B O OAB 16 y= 4 3 x+4 x y A B A 17 y=a(x-h) 2 +k -8 y=-2x 2 -2x+3 _ 18 ABC 60 BAC 45 ABC AB= 2 2 D BC AD O AB AC E F EF EF 19 6 20 21 8 22 23 24 10 25 12 26 14 78 19 6 ABCD 20 8 2 x 2 1 y 2 x A B A B y C 1 A B C 2 21 8 C D E 1 2 22 10 y=ax 2 +bx+c x A
4、 B A 1 0 B 5 0 C 0 5 M 1 2 23 10 A B A 0 2 D 1 AB 2 B C 3 OBD D 24 10 20 40 Q( ) t( ) t( ) 1 3 6 10 36 Q( ) 94 90 84 76 24 40 20 y1( / ) t( ) y1 1 4 t t t ) 20 y2( / ) t( ) y2 1 2 t t t ) (1) Q( ) t( ) (2) 40 (3) 20 a (a 4) 20 t a 25 12 1 ABCD AC=BD A ABCD 1 2 2 ABCD 6 3 3 ABCD M OM AD 26 14 xOy y a
5、x 2 2ax 3a(a 0) x A B ( A B ) A l y kx b y C D CD 4AC. (1) A l ( k b a ) (2) E l 5 4 a (3) P Q A D P Q P 4 48 1 2 3 4 5 6 7 8 9 10 11 12 B A C A B D C C B C C C 4 24 13. 1 ) 2 ( 2 x14. 120 15. 9 16. 7,3 17. x x y x x y 8 2 8 2 2 2 18. 3 19 6 20 21 8 22 23 24 10 25 12 26 14 78 19 6 5 1 20 8 1 A(2,0),
6、B(-2,O) ,C(0,-2) 4 2 .8 21 8 1 OD AB C O D AD= BD AOD=52 DEB=26 .(4 ) 2 OD AB OD AB, AC=BC, Rt AOC OC=“3“ AO=5, , AC=4, AB=2AC=8 .(8 ) 22 10 1 y=a x+1 x 5 C 0 5 5 =5 a= 1 y= x 2 +4x+5 .5 2 y= x 2 +4x+5= x 2 2 +9 M 2 9 MAB = 5+1 9=27 10 23 (10 ) 1 AB ODB= OAB ODB=60 OAB=60 AOB AB C OBA=30 AB=2OA=4 C
7、r=2 . 3 2 Rt OAB OB 2 +OA 2 =AB 2 OB=2 3 B 2 3 0 . 5 C CE OA E CF OB F OE=AE=1 OF=BF= 3 CE= 3 CF=1 C 3 1 7 (3)D( 3 ,3 ) .(10 ) 24 12 (1) y kt b (36 24) (10 76) y kt b 36k b 24 10k b 76 k 2 b 96. y 2t 96 .(3 ) (2) W W 2t 96 1 4 t 25 20 t 2t 96 1 2 t 40 20 t W 1 2 t 14 2 578 t t 44 2 16 t t t 14 W 578
8、 t W x t 21 W 513 (7 ) t 14 578 (3) W ( 2t 96) 1 4 t 25 20 a ( t W 1 2 t 2(a 7) 2 2(a 17) 2 t t x 2(a 7 a a 4 a .(10 ) 25 1 .(2 ) 2 OB OD H 2 BH=DH OH=3 =54 (7 ) 3 OM=AD .(8 ) OB OC OA OD E 3 .(12 ) 26 (1) y ax 2 2ax 3a a(x 1)(x 3) A( 1 0) CD 4AC xD 4. D(4 5a) A( 1 0) D(4 5a) l y ax a (3 ) (2) E x A
9、D F. E(x ax 2 2ax 3a) F(x ax a) EF yE yF ax 2 3ax 4a. S ACE S AEF S CEF 1 2 EF(xE xA) 1 2 EF(xE xC) 1 2 EF(xC xA) 1 2 (ax 2 3ax 4a) 1 2 a x 3 2 2 25 8 a 25 8 a. 25 8 a 5 4 a 2 5 (7 ) (3) A( 1 0) D(4 5a) xP 1 AD AD AD QP AP QD. xD xA xP xQ xQ 4. x 4 y a(x 1)(x 3) 21a. Q( 4 21a) yD yA yP yQ yP 26a. P(1 26a) AP 2 QD 2 2 2 (26a) 2 8 2 (16a) 2 . 7a 2 1. a 7 7 . P 1 26 7 7 10 AD AD PQ xD xA xP xQ xQ 2. Q(2 3a) yD yA yP yQ yP 8a. P(1 8a) AD 2 PQ 2 5 2 (5a) 2 1 2 (11a) 2 . 4a 2 1. a 1 2 . P(1 4) 13 P 1 26 7 7 P(1 14
