MathDB
Canadian Students Math Olympiad 2011 Problem 3

Source:

July 19, 2011
inequalities proposedinequalities

Problem Statement

Find the largest CRC \in \mathbb{R} such that
x+z(xz)2+x+w(xw)2+y+z(yz)2+y+w(yw)2+cyc1xCx+y+z+w\frac{x+z}{(x-z)^2} +\frac{x+w}{(x-w)^2} +\frac{y+z}{(y-z)^2}+\frac{y+w}{(y-w)^2} + \sum_{cyc} \frac{1}{x} \ge \frac{C}{x+y+z+w}
where x,y,z,wR+x,y,z,w \in \mathbb{R^+}.
Author: Hunter Spink