Question 165
Determine all functions $f: \mathbb{R} \rightarrow \mathbb{R}$ with the property
$$
f(f(x)+y)=2 x+f(f(y)-x)
$$
for all $x, y \in \mathbb{R}$.
$$
f(f(x)+y)=2 x+f(f(y)-x)
$$
for all $x, y \in \mathbb{R}$.
MathNet 2003 — Part 01 Question 165
Math Olympiad Vault · MathNet 2003 — Part 01