Prove \frac{x-y}{x^6-y^6}\leq \frac{4}{3}(x+y) if x^4-y^4=x-y
Source: Iran National Olympiad 2017, Second Round, Problem 4
April 21, 2017
algebra2-variable inequalityInequalityinequalities
Problem Statement
Let be two positive real numbers such that . Prove that