Consider the function
\({\rm{f}}\left( {\rm{x}} \right) = \left\{ {\begin{array}{*{20}{c}} {\frac{{\tan {\rm{kx}}}}{{\rm{x}}}}&{{\rm{x}} \le 0}\\ {3{\rm{x}} + 2{{\rm{k}}^2}}&{{\rm{x}} \ge {\rm{0}}} \end{array}} \right.\)
What is the non-zero value of k for which the function is continuous at x = 0?1
1/4
2
1/2
3
1
4
2