Question 13
Find all functions $f:\mathbb R\to\mathbb R$ such that
$$
f(x+yf(x+y))=y^2+f(x)f(y)
$$
for all $x,y\in\mathbb R$.
$$
f(x+yf(x+y))=y^2+f(x)f(y)
$$
for all $x,y\in\mathbb R$.
MathNet 2021 — Part 06 Question 13
Math Olympiad Vault · MathNet 2021 — Part 06