It is proved that √ A & sup2; + B & sup2; + C & sup2; / 3 ≥ a + B + C / 3 ≥ & sup3; √ ABC (where a, B, C ∈ positive real numbers, and each pair is unequal),

It is proved that √ A & sup2; + B & sup2; + C & sup2; / 3 ≥ a + B + C / 3 ≥ & sup3; √ ABC (where a, B, C ∈ positive real numbers, and each pair is unequal),

(a+b+c)^2=a^2+b^2+c^2+2(ab+bc+ac)=3*³√abc