$3$

Mark for Review

$f(x)=\{\begin{array}{ccc}\frac{|x|}{x}& \text{f}\text{o}\text{r}& x0\\ 0& \text{f}\text{o}\text{r}& x=0\end{array}$

If $f$ is the function defined above, then $\underset{x0}{lim}f(x)$ is

$1$

nonexistent