Discuss the continuity of the function $f$, where $f$ is defined by $ f(x) = \left\{ \begin{array} {1 1} 2x ,& \quad\text{ if $ x $ < 0}\\ 0,& \quad\text{if $ 0 $ \(\leq x\) \(\leq1\)}\\ 4x ,& \quad\text{ if $ x $ > 1}\\ \end{array} \right. $

Question

$\begin{array}{1 1} \text{The point of discontinuity is x=-1} \\ \text{The point of discontinuity is x=1} \\ \text{The point of discontinuity is x=0} \\ \text{The point of discontinuity is x=2}\end{array} $