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Prove the inequality for positive real x - [VMO 2011]

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January 11, 2011
inequalitiesinequalities proposed

Problem Statement

Prove that if x>0x>0 and nN,n\in\mathbb N, then we have xn(xn+1+1)xn+1(x+12)2n+1.\frac{x^n(x^{n+1}+1)}{x^n+1}\leq\left(\frac {x+1}{2}\right)^{2n+1}.