MathDB

1b

Part of 2017 Abels Math Contest (Norwegian MO) Final

Problems(1)

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

Source: Norwegian Mathematical Olympiad 2017 - Abel Competition p1b

9/3/2019
Find all functions f:R→Rf : R \to R which satisfy f(x)f(y)=f(x+y)+xyf(x)f(y) = f(x + y) + xy for all x,y∈Rx, y \in R.
functionfunctional equationalgebra