Question 91
Find all real functions $f$ from $\mathbb{R} \rightarrow \mathbb{R}$ satisfying the relation
$$
f\left(x^{2}+y f(x)\right)=x f(x+y)
$$
$$
f\left(x^{2}+y f(x)\right)=x f(x+y)
$$
MathNet 2015-part-03 — 191 problems (EN–VI) Question 91
Math Olympiad Vault · MathNet 2015-part-03 — 191 problems (EN–VI)