Question
Draw the graph of the signum function, $f : R \rightarrow R$, defined by $f ( x )=\left\{\begin{array}{l}\frac{x}{\mid x}, \text { when } x \neq 0 \\ 0, \text { when } x=0\end{array}\right.$ or $f(x)=\left\{\begin{array}{l}1, \text { if } x>0 \\ 0, \text { if } x=0 \\ -1, \text { if } x<0\end{array}\right.$

