MathDB
Inequality in XMO

Source: XMO 15th

April 30, 2024
inequalities

Problem Statement

nn is a integer and a1,a2,,an[1,1]a_1, a_2, \ldots, a_n\in[-1,1] are real numbers with i=1nai=0 \sum_{i=1}^{n}a_{i}=0 ,try to find the maximum value of 1i,jn,ijaiaj2 \sum_{1\leq i , j \leq n , i\ne j}|a_{i}-a^2_j|