Explain why the function is discontinuous at the given number a$.($Select all that apply.$)$

f$($x$)=$

cos$($x$)$ if x $<00$ if x $=01$ x$2$ if x $>0$

$$a $=0$

f$(0)$ and$$lim$$x$0$f$($x$)$ are finite, but are not equal.

lim$$x$0+$f$($x$)$ and$$lim$$x$0$f$($x$)$ are finite, but are not equal.

lim$$x$0$f$($x$)$ does not exist.

f$(0)$ is undefined.

none of the above