1、 2018 12 2017-2018 30 3 30 1 2 3 4 5 6 7 8 9 10 B C D A A D B C D B 70 5 3 15 11 1 2 12 13 2 14 4 15 1 7 55 16 8 1 1 23 x 2 23 x 2 x 2 x 1 17 6 1 6 (0 2) (0 0) (0 1) ( 2 2) ( 2 0) ( 2 1) (2) Q x 2 Q x 2 6 1 3 . 18 7 1 1 ABC y A1B1C1 2 ABC B A2BC2 BC S= = 19 7 1 AB O ACB=90 ABC= D =60 BAC=30 BAE = BA
2、C EAC=30 60 =90 BA AE AE O 2 OC OB=OC, ABC=60 OBC OB=BC=4 , BOC=60 AOC=120 7 AC 3 8 180 4 120 20 8 O OM AB M.(1 O AC D OD AC ADO AMO 9 ABC AO BC DAO MAO OM OD AB O (2) O ON BE N OF NG NF 1 2 GF O BC OB 2. OBM MBO BOM BM 1 2 BO 1 OM OB 2 BM 2 O A B C D E 3. BE AB OMBN ON BM OF OM 3 NF 3 2 1 2 2 GF 2N
3、F 2 2. (1) 21 9 1 y 2x (2) 150 x (x 20)y 150 (x 20)( 2x 80) 150 x 2 60x 875 0 (x 25)(x 35) 0 x1 25 x2 35( ) 25 (3) w (x 20)( 2x 80) 2x 2 120x 1600 2(x 30) 2 200 x 30 w 20 28 x 30 y x x 28 w 2(28 30) 2 200 192( ) 28 192 22 10 (1) y a(x 2) 2 9 y A(0 5) 9 5 1 y (x 2) 2 9 x 2 4x 5. (2) y 0 x 2 4x 5 0 1
4、1 x2 5 1 0) B(5 0) AB y mx n 5) B(5 0) 1 n 5 AB y x 5. P(x x 2 4x 5) x 5) x 2 4x 5 x 5 x 2 5x 4 APCD 1 2 2( x 2 5x) 2x 2 10x x 10 2 5 2 P( 5 2 35 4 ) S APCD 25 2 . (3) M MH H AENM MN AE OE x 3 x 1. x 1 M 8 x 3 M 8 M1(1 8) M2(3 8) A(0 5) E( 1 0) AE y 5x 5 MN y 5x b N x 2 10 b) 2 OA 2 OE 2 26 AE 2 AE 2 M1(1 8) M2(3 8) M1 M2 x 2 N 1N M2N 2 (1 2) 2 8 (10 b) 2 1 (b 2) 2 26 3 b 7 b 13 10 b 3. M (1 8) N (2 13) M (3 8) N (2 3)
