Question

已知x+2y=1,则2^x+4^y的最小值为(　　)

A.8                       B.6                    C.2                 D.3

Answer 1

解析:2^x+4^y=2^x+2^2y≥2=2=2,即2^x+4^y≥2.?

当且仅当2^x=2^2yx=2y=时,取“=”.

答案:C