Question 136
A function $f: \mathbb{R} \to \mathbb{R}$ satisfies the equality $f(f(x)) = x f(x) + x - 1$ for all real numbers $x$.
a) Find $f(-1)$.
b) Find all possible values of $f(1)$.
a) Find $f(-1)$.
b) Find all possible values of $f(1)$.