已知x满足不等式2(log 1/2x) +7log1/2x+3≤0,3Q
问题描述：
已知x满足不等式2(log 1/2x) +7log1/2x+3≤0,3Q
已知x满足不等式2(log 1/2x) +7log1/2x+3≤0,求函数f(x)=(log2四分之x)*(log2二分之x)的最大值和最小值
答
设T=log(1/2)(x) 则有:2T^2+7T+3<=0 (2T+1)(T+3)<=0 则:-3=<T<=-1/2 即:-3=<log(1/2)(x)<=-1/2 故:X属于[√2,8] f(x) =[log2(x/4)]*[log2(x/2)] =[log2(x)-log2(4)]*[log2(x)-log2(2)] =[lo...