MathDB
Poland97?

Source:

November 19, 2006
functioninequalitiesHi

Problem Statement

a,b,c3/4a,b,c \geq-3/4 and a+b+c=1a+b+c=1. Show that: a1+a2+b1+b2+c1+c2910\frac{a}{1+a^{2}}+\frac{b}{1+b^{2}}+\frac{c}{1+c^{2}}\leq \frac{9}{10}