3a^3+2b^3>=3a^2b+2ab^2
问题描述：
3a^3+2b^3>=3a^2b+2ab^2
答
=> 3a^2(a-b)+2b^2(b-a)>=0
=> (3a^2-2b^2)(a-b)>=0
=> a>=b 或 -(2/3)^0.5b=-(2/3)^0.5b 或 b