3. (1.5 pts.) Consider the function $y = f(x)$, defined piecewise as follows:
$f(x) = \begin{cases} x - 1 & \text{if } x \le 0 \\ 2x & \text{if } 0 < x < 1 \\ 3 - x & \text{if } x \ge 1 \end{cases}$
(a) Sketch an accurate graph of $y = f(x)$ in an xy-plane.
(b) Evaluate $\lim_{x \to 1} f(x)$.
(c) At which values of $x$, if any, does $f(x)$ have a discontinuity?