The function defined by
\(\rm f(x) = \left\{ \begin{matrix} \dfrac{|x|}{x}, & x \ne 0 \\\ 0, & x = 0 \end{matrix} \right.\)
at x = 0 is
1
continuous
2
discontinuous at x = 0 and has discontinuity of first kind
3
discontinuous at x = 0 and has removable discontinuity
4
discontinuous at x = 0 and has discontinuity of second kind