MathDB
Simple inequality

Source: 2016 Nigerian Senior MO Round 2

November 16, 2022
algebraInequalityinequalities

Problem Statement

Given that a,b,c,dRa, b, c, d \in \mathbb{R}, prove that (ab+cd)2(a2+c2)(b2+d2)(ab+cd)^2 \leq (a^2+c^2)(b^2+d^2).