y=log2 x/4 ×log4 x/2=lg(x/4)/lg2 * lg(x/2)/lg4=(lgx-lg4)/lg2 * (lgx-lg2)/(2lg2)=(lgx-2lg2) * (lgx-lg2) / [2(lg2)^2]=[(lgx)^2 - 3lg2 lgx +2(lg2)^2] / [2(lg2)^2]=[(lgx - 3/2 lg2)^2 -1/4 (lg2)^2] / [2(l...