关于函数Y=㏒a(a²x)×㏒a²（ax)的最小值是－1/8.最大值是0.其定义域为2≤X≤4.求a的值

y=(loga(a^2)+loga(x))*(loga^2(a)+loga^2(x))=(2+loga(x))*(1/2+1/2loga(x))=1/2(loga(x))^2+3/2loga(x)+1令t=loga(x)则y=(1/2)t^2+(3/2)t+1,为t的二次函数,-b/2a=-3/2 ,(4ac-b^2)/4a=-1/8画出y--t图象（自己画下吧...