Question

已知x满足2^x大于等于256,且log2X大于等于1/2.求函数f(x)=log2(x/2)乘log根号2(根号x/2

Answer 1

2^x>=256=2^8,x>=8.

logx>=1/2,x>=√2.

∴x>=8.

f(x)=log(x/2)*log(x/2)

=2(logx-1)^2,

logx>=3,

∴f(x)|min=8.f(x)没有最大值.