MathDB
Inequality with x+y+z=1

Source: China TST 2006

June 18, 2006
inequalitiesfunction

Problem Statement

Given three positive real numbers x x, y y, z z such that x \plus{} y \plus{} z \equal{} 1, prove that \frac {xy}{\sqrt {xy \plus{} yz}} \plus{} \frac {yz}{\sqrt {yz \plus{} zx}} \plus{} \frac {zx}{\sqrt {zx \plus{} xy}} \le \frac {\sqrt {2}}{2}.