求函数y=log2 x/2*log2x/4,x∈[2√2,8]的值域

求函数y=log2 x/2*log2x/4,x∈[2√2,8]的值域
求函数y=log2 x/2*log2x/4,x∈[2√2,8]的值域

求函数y=log2 x/2*log2x/4,x∈[2√2,8]的值域
y=(log2 x)/(log2 1/2)*(log2 x)/(log2 1/4)
=(log2 x)^2/2
令t=log2 x,3/2