实数a,b满足a+2b=2,求2^a+2^b的最小值
问题描述：
实数a,b满足a+2b=2,求2^a+2^b的最小值
答
a+2b=2
a=2-2b
2^a+2^b
=2^(2-2b)+2^b
=4/2^2b+2^b
=4/4^b+2^b
=4/4^b+2^b/2+2^b/2
≥3*(4/4^b*2^b/2*2^b/2)的3次方根
=3
所以,2^a+2^b的最小值为3