Question 181
Find all real numbers $a$ such that there exists a function $f: \mathbb{R} \rightarrow \mathbb{R}$ satisfying the following conditions
i) $f(1) = 2016$;
ii) $f(x + y + f(y)) = f(x) + ay$ for all real numbers $x, y$.
i) $f(1) = 2016$;
ii) $f(x + y + f(y)) = f(x) + ay$ for all real numbers $x, y$.