1、 2018 3 1 y= a-1 x a A B C D 2 A sinA=0.75 ( ) A A0 BD M BC CD P Q 1 M C 2 BD 3 PQ BD 24 8 A B B A 30 A 60 A B 75 C B CB 25 12 A 4 0 B 0 4 C 2 0 1 2 M M m AMB S S m S 3 P Q y= x P Q B O Q 2017 2018 20 1 y=2x+2 A 0 2 OA=2 tan AHO=2 OH=1 MH x M 1 M y=2x+2 M 4 M 1 4 M y= k=1 4=4 4 2 N a 1 x 0 a=4 N 4 1
2、 N N x N1 MN1 x P PM+PN N N1 x N 4 1 N1 4 1 MN1 y=kx+b k= b= MN1 y=0 x= P 0 10 21 1 800 x / x-2) 500- 800 . x 2 -10x+24 0. 4 x 6 240% x x 4.8 . 4 x 4.8 4 x 4.8 800 . 5 2 W x / W= x-2)(500- =-100x 2 +1000x-1600 =-100(x-5) 2 +900. W x , x=“4.8“ W W =- 4.8-5)2+900=896 4.8 / 896 . 10 22 1 ABCD D= DCG=90 E CD DE=CE DEF= CEG EDF ECG EF=EG BE FG BE FG BF=BG 4 2 AD= 10 23 1 2 2 3 3 5 24 8 25 1 2 2 5 3 5 1 1
