Question 4
Find all functions $f:\mathbb R\setminus\{-1\}\to\mathbb R$ such that
$$f(x)+f(y)=(x+y+2)f(x)f(y)$$
for all $x,y\in\mathbb R\setminus\{-1\}$.
$$f(x)+f(y)=(x+y+2)f(x)f(y)$$
for all $x,y\in\mathbb R\setminus\{-1\}$.
MathNet 2013 Question 4
Math Olympiad Vault · MathNet 2013