HoW???????
Source: New Ineq
August 26, 2008
InequalityoptimizationmaximizationIMO ShortlistIMO Shortlist 1972
Problem Statement
The least number is and the greatest number is among satisfying a_1 \plus{}a_2 \plus{}...\plus{}a_n \equal{}0. Prove that
a_1^2 \plus{}\cdots \plus{}a_n^2 \le\minus{}nmM