MathDB
Lithuanian TST 2014 #3

Source:

April 20, 2014
linear algebramatrixquadraticsalgebrasystem of equationsalgebra solved

Problem Statement

Given such positive real numbers a,ba, b and cc, that the system of equations: {a2x+b2y+c2z=1xy+yz+zx=1 \{\begin{matrix}a^2x+b^2y+c^2z=1&&\\xy+yz+zx=1&&\end{matrix} has exactly one solution of real numbers (x,y,z)(x, y, z). Prove, that there is a triangle, which borders lengths are equal to a,ba, b and cc.