MathDB
Power colombian inequality

Source: IberoAmerican Olympiad For University Students

July 10, 2011
inequalitiesinductioninequalities proposed

Problem Statement

Prove that for all positive integers nn and for all real numbers xx such that 0x10\le x\le1, the following inequality holds: (1x+x22)n(1x)nx2\left(1-x+\frac{x^2}{2}\right)^n-(1-x)^n\le\frac{x}{2}.