calculate the limit or determine that it does not exist. If a limit is or $$$,$ say so$.$

$($a$)$ lim

x$6$

x$236$

x $+6$

$($b$)$ lim

x$6$

x $36$

$($x $6)2$

$($c$)$ lim

x$6$

x$236$

x $6$