MathDB
Determine the range

Source: Canadian Mathematical Olympiad - 2009 - Problem 3.

May 4, 2011
calculusinequalities proposedinequalities

Problem Statement

Define f(x,y,z)=(xy+yz+zx)(x+y+z)(x+y)(y+z)(z+x)f(x,y,z)=\frac{(xy+yz+zx)(x+y+z)}{(x+y)(y+z)(z+x)}. Determine the set of real numbers rr for which there exists a triplet of positive real numbers satisfying f(x,y,z)=rf(x,y,z)=r.
Back to ProblemsView on AoPS