Question 93
Find all functions $f : \mathbb{R} \to \mathbb{R}$ such that for all real $x, y$
$$
f(x - f(x/y)) = x f(1 - f(1/y))
$$
and
a) $f(1 - f(1)) \neq 0$;
b*) $f(1 - f(1)) = 0$.
$$
f(x - f(x/y)) = x f(1 - f(1/y))
$$
and
a) $f(1 - f(1)) \neq 0$;
b*) $f(1 - f(1)) = 0$.