f(f(x)) = x^2 - 2
Source: Vietnam TST 1990, Problem 3
July 29, 2008
functionalgebra unsolvedalgebra
Problem Statement
Prove that there is no real function satisfying f\left(f(x)\right) \equal{} x^2 \minus{} 2 for all real number .
Source: Vietnam TST 1990, Problem 3