MathDB
if (x+\sqrt{x^2 +1}) (y+\sqrt{y^2 +1}) = 1, then x+y = 0.

Source: All Russian MO 1994 ARO IX P1

July 29, 2018
algebraradicalequation

Problem Statement

Prove that if (x+x2+1)(y+y2+1)=1(x+\sqrt{x^2 +1}) (y+\sqrt{y^2 +1}) = 1, then x+y=0x+y = 0.