\sum_{cyc} (a^3-b^3)^2+3\sum_{cyc}(a^2-b^2)^2+6(a-b)(b-c)(c-a)(ab+ bc+ca) >= 0.
Source: Mathcenter Contest / Oly - Thai Forum 2011 (R1) p1 sl-1 https://artofproblemsolving.com/community/c3196914_mathcenter_contest
November 14, 2022
inequalitiesalgebra
Problem Statement
Let . Prove that (LightLucifer)