A cubic function $f(x)$ satisfies $$xf(x) - f(x) = 3x^4 - 3x$$ for all real numbers $x$. Find the value of $\int_{-2}^{2} f(x)\,dx$. [3 points] (1) 12 (2) 16 (3) 20 (4) 24 (5) 28
A cubic function $f(x)$ satisfies
$$xf(x) - f(x) = 3x^4 - 3x$$
for all real numbers $x$. Find the value of $\int_{-2}^{2} f(x)\,dx$. [3 points]\\
(1) 12\\
(2) 16\\
(3) 20\\
(4) 24\\
(5) 28