MathDB
Maximal value

Source: 2022 IMOC A2

September 5, 2022
inequalities

Problem Statement

Given positive integer n>2,n>2, consider real numbers a1,a2,,ana_1,a_2,\dots, a_n satisfying a12+a22+an2=1.a^{2}_1+a^2_2+\dots a^2_n=1. Find the maximal value of a1a2+a2a3++ana1.|a_1-a_2|+|a_2-a_3| +\dots +|a_n-a_1|. Proposed by ltf0501