Question

如图,点A(a,2)是正比例函数y=k1x(k≠0）与反比例函数y=4/x的图像在第一象限内的交点,过点A作直线AB∥y

Answer 1

(1)

A(a,2)在反比例函数y=4/x的图像上,2 = 4/a,a = 2

A(2,2),B(2,0)

A在y=kx的图像上:2 = 2k,k = 1

y = x

M在第一象限内,在A点上方,∠MOA小于∠AOy = 45°

0 < x < 45

(2)

M(m,4/m),D(2,4/m)

MD = 2 - m,OA = 2,BD = 4/m

四边形OADM是梯形,面积S = 4 = (1/2)(MD + OA)*BD = (1/2)(2 - m + 2)*4/m

m = 4/3

CM = 4/3 - 0 = 4/3

DM = 2 - 4/3 = 2/3

CM = 2DM