MathDB
f(x - f(y)) = f(x + y) + f(y)

Source: AIMO 2008, TST 6, P3

January 4, 2009
functionalgebra unsolvedalgebra

Problem Statement

Determine all functions f:RR f: \mathbb{R} \mapsto \mathbb{R} with x,yR x,y \in \mathbb{R} such that f(x \minus{} f(y)) \equal{} f(x\plus{}y) \plus{} f(y)