a+2b=2a=2-2b2^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)的册梁御3次方根=3所以渣吵,2^a+2^b的最州岩小值为3