MathDB
An Inequality

Source: Excursion

June 25, 2020
inequalitiesInequalitypositive integersreal number

Problem Statement

Prove that for every positive integer nn and a non-negative real number aa, the following inequality holds: n(n+1)a+2n4a(1+2++n).n(n+1)a+2n \geqslant 4\sqrt{a}(\sqrt{1}+\sqrt{2}+\dots+\sqrt{n}).