MathDB
functional for starters II f(x)f(y) = f(x + y) + xy

Source: Norwegian Mathematical Olympiad 2017 - Abel Competition p1b

September 3, 2019
functionfunctional equationalgebra

Problem Statement

Find all functions f:RRf : R \to R which satisfy f(x)f(y)=f(x+y)+xyf(x)f(y) = f(x + y) + xy for all x,yRx, y \in R.