Let f(x) = \(\left\{\begin{matrix} x^2|\cos\frac{\pi}{h}|, & x \neq 0 \\ 0, & x = 0 \\ \end{matrix}\right.\) for x ∈ R, then f is
1
continuous but not differentiable at x = 0
2
continuous and differentiable at x = 0
3
does not exists at x = 0
4
None of the above