Question 99
Find all functions $f$ from real numbers to real numbers such that
$$
2f((x+y)^2) = f(x+y) + (f(x))^2 + (4y-1)f(x) - 2y + 4y^2
$$
holds for all real numbers $x$ and $y$.
$$
2f((x+y)^2) = f(x+y) + (f(x))^2 + (4y-1)f(x) - 2y + 4y^2
$$
holds for all real numbers $x$ and $y$.