函数y=log2(x)+logx(2x)的值域是

问题描述:

函数y=log2(x)+logx(2x)的值域是

y=log2(x)+logx(2x)=log2(x)+logx(2)+logx(x)=log2(x)+logx(2)+1
log2(x)与logx(2)互为倒数,故值域为(-∞,-1]∪[3,+∞)