Question 58
Find all functions $f : \mathbb{R}^{+} \to \mathbb{R}^{+}$ such that for all $x, y, z \in \mathbb{R}^{+}$
$$
f(x + f(y) + f(f(z))) = z + f(y + f(x)).
$$
$$
f(x + f(y) + f(f(z))) = z + f(y + f(x)).
$$
MathNet 2023-part-03 — 191 problems (EN–VI) Question 58
Math Olympiad Vault · MathNet 2023-part-03 — 191 problems (EN–VI)