MathDB
japan 2001

Source: Titu Andreescu 2000-2001 , page 227

February 21, 2004
inequalitiesinequalities solvedSides of a triangle3-variable inequalitySymmetric inequalityJapan2001

Problem Statement

Three nonnegative real numbers satisfy a,b,ca,b,c satisfy a2b2+c2,b2c2+a2a^2\le b^2+c^2, b^2\le c^2+a^2 and c2a2+b2c^2\le a^2+b^2. Prove the inequality (a+b+c)(a2+b2+c2)(a3+b3+c3)4(a6+b6+c6).(a+b+c)(a^2+b^2+c^2)(a^3+b^3+c^3)\ge 4(a^6+b^6+c^6). When does equality hold?