Question 96
Find all the functions $f: \mathbb{R} \rightarrow \mathbb{R}$ that fulfill the following equation for all real $x, y$: $$
f\left(x^{4}+y^{4}\right)=x f\left(x^{3}\right)+y^{2} f\left(y^{2}\right)
$$
f\left(x^{4}+y^{4}\right)=x f\left(x^{3}\right)+y^{2} f\left(y^{2}\right)
$$