2.7.6 Function properties

Problem: Find the discontinuity points of the function and determine their types: \[ f(x)=\left\{\begin{array}{cc} \frac{4}{x+3}, & x \in(-\infty ;-4) \\ 2 x^{2}+5 x-3, & x \in(-4 ; 2) . \\ \frac{-2}{x-1}, & x \in[2 ;+\infty) \end{array}\right. \]