Question 44
Find the functions $f : \mathbb{R} \to \mathbb{R}$, satisfying
$$
f(f(x)) + y \cdot f(x) \leq x + x \cdot f(f(y)),
$$
for every real numbers $x$ and $y$.
$$
f(f(x)) + y \cdot f(x) \leq x + x \cdot f(f(y)),
$$
for every real numbers $x$ and $y$.