[10 Points] Determine whether the function
$f(x) = egin{cases} x^2 - 4x & \text{if } x \le -2\\ \frac{-30x}{x^2 + 1} & \text{if } -2 < x < -1\\ 4x + 1 & \text{if } x > -1 \end{cases}$
is continuous/discontinuous at $x = -2, -1, 1$. For each discontinuity, identify its type.