olymmath

NO-ABEL 2016

Abel Competition 2016.

Other problems

Problem 4

Find all functions f:R→Rf : \mathbb{R} \to \mathbb{R} such that f(x)f(y)=∣x−y∣⋅f(xy+1x−y)f(x) f(y) = |x - y| \cdot f \left( \frac{xy + 1}{x - y} \right) Holds for all x≠y∈Rx \not= y \in \mathbb{R}