MathDB
A fairly inelegant inequality

Source: Germany 2012 - Problem 4

December 5, 2022
inequalitiesalgebrasuquare rootreal number

Problem Statement

Let a,ba,b be positive real numbers and n2n\geq 2 a positive integer. Prove that if xnax+bx^n \leq ax+b holds for a positive real number xx, then it also satisfies the inequality x<2an1+2bn.x < \sqrt[n-1]{2a} + \sqrt[n]{2b}.