Find the arclength function of vec$($r$)($t$)=(3-3$t$)$hat$()+4$that$($j$)$ starting from the point $(3,0).$

a$.$ Using your results, find the distance travelled away from $(3,0)$ after t$=4.$

b$.$ Find the arclength parametrization of vec$($r$).$ That is$,$ rewrite vec$($r$)$ as a function of s$,$ the

arclength of vec$($r$).$

$(10$ points each$)$