Question 65
Find all functions $f: \mathbb{R} \to \mathbb{R}$ such that
$$
f(x^3 + y^3) = f(x^3) + 3x^3f(x)f(y) + 3f(x)(f(y))^2 + y^6f(y)
$$
for every two real numbers $x$ and $y$.
$$
f(x^3 + y^3) = f(x^3) + 3x^3f(x)f(y) + 3f(x)(f(y))^2 + y^6f(y)
$$
for every two real numbers $x$ and $y$.