The position of a particle is given by the function x$($t$)=(3$t$36$t$2+12)$ meters, where t is in seconds.

a$)(20$ points$)$ Find the time or times when the velocity $=0$ m$/$s$.$

b$)(20$ points$)$ Find the position of the particle at all times where the velocity $=0$ m$/$s$.$

c$)(20$ points$)$ Find the acceleration of the particle at all times where the velocity $=0$ m$/$s$.$