Question 2
Consider the function $g(x) = \frac{2x}{1+x^2}$. Find all function $f(x)$ defined and continuous on the interval $(-1; 1)$ which satisfy the condition:
$$
(1 - x^2)f(g(x)) = (1 + x^2)^2 f(x)
$$
for every $x \in (-1; 1)$.
$$
(1 - x^2)f(g(x)) = (1 + x^2)^2 f(x)
$$
for every $x \in (-1; 1)$.