已知函数y=log以a为底a^2x的对数*log以a^2为底的ax的对数,当x属于[2,4]时,y的取值范围是[-1/8,0]

y=loga(a^2*(x))*loga^2(ax)
=[2x*lg(a)/lg(a)]*{[lg(a)+lg(x)]/2lg(a)}
=x+xlg(x)/lg(a)
若a>1则lg(a)>0,又因为x属于[2,4] 所以y单调增
此情况与题意不符,舍去．所以0