SE-SKOLORNAS 2014 Problem 3

Determine all functions $f: \mathbb R \to \mathbb R$ , such that $f (f (x + y) - f (x - y)) = xy$ for all real $x$ and $y$ .

Dataset text AI-MO AoPS. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.