f(x)=[log2(x)-2][log2(2/x)令t=log2(x)1≤t≤3原函数可化为：y=(t-2)(1-t) = - t^2+3t-2 抛物线y(t)开口向下,对称轴为;t=3/2,函数y(t)在[1,3] 上先增后减,且增区间短,增区间长；y(max)=y(3/2)=1/4y(min)=y(3)= - 2...