Sketch graphs by hand and use them to make approximations for each of the limits. If a two-sided limit does not exist, describe the one-sided limits.
$$
\lim _{x \rightarrow 1} f(x), \text { for } f(x)=\left\{\begin{array}{r}
x^{2}+1, \text { if } x<1 \\
3, \text { if } x=1 \\
3-x, \text { if } x>1
\end{array}\right.
$$