已知-3≤log以1/2为底x的对数≤-1/2,求函数y=(log2为底 x/2的对数)(log2为底 x/4的对数)的值域

-3=log(1/2)8,-1/2=log(1/2)√2因为0＜1/2＜1,因此为减函数,√2≤x≤8y=(log2 x-log2 2)(log2 x-log2 4)=(log2 x -1)(log2 x -2)√2≤x≤8,1/2≤log2 x≤3设log2 x=ty=t²-3t+2=(t-3/2)²-1/41/2≤t≤3当t=3...