3. The position function of a cheetah moving across level ground in a straight line chasing prey is given by, s(t) = 13 - 15t2 + 63t , where s is measured in metres and t is in seconds, t 2 0. a) Find the velocity function v(t) and acceleration function a(t). At what time(s) is the cheetah at rest? and at what position(s) is the cheetah at that time? At what time is the cheetah's acceleration 0? What is his position at that time? Find the total distance travelled by the cheetah in the first 12 seconds. (8 marks)