你看错了:应该是:a+b+c≥3×3∧√abc,我想推导过程是这样的:a+b+c=(3∧√a)^3+(3∧√b)^3+(3∧√c)^3≥3(3∧√a)(3∧√b)(3∧√c),即:a+b+c≥3×3∧√abc
应该是a+b+c≥3Χ_3√abc