Let a1,a2,...,an be positive real numbers such that a1+a2+...+an=a21+a22+...+a2nProve that ∑1≤i<j≤naiaj(1−aiaj)≥0Võ Quốc Bá Cẩn.
Source: 2015 Saudi Arabia IMO TST II p3
Tags: inequalities, algebra, n-variable inequality
Let a1,a2,...,an be positive real numbers such that a1+a2+...+an=a21+a22+...+a2nProve that ∑1≤i<j≤naiaj(1−aiaj)≥0Võ Quốc Bá Cẩn.