MathDB
INMO 2015

Source: inmo 2015 #3

February 1, 2015
functiontrigonometryalgebrafunctional equationalgebra unsolved

Problem Statement

Find all real functions f:R→Rf: \mathbb{R} \to \mathbb{R} such that f(x2+yf(x))=xf(x+y)f(x^2+yf(x))=xf(x+y).