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\frac{a^2+b^2}{a^4+b^4}+\frac{b^2+c^2}{b^4+c^4}+\frac{c^2+a^2}{c^4+a^4}

Source: Moldova JTST 2009

May 10, 2023
inequalities

Problem Statement

Real positive numbers a,b,ca, b, c satisfy abc=1abc=1. Prove the inequality a2+b2a4+b4+b2+c2b4+c4+c2+a2c4+a4a+b+c.\frac{a^2+b^2}{a^4+b^4}+\frac{b^2+c^2}{b^4+c^4}+\frac{c^2+a^2}{c^4+a^4}\leq a+b+c.