An endurance training runner begins at point A and races to point B, then switches and races again to point A, then switches and races again to point B. The position for the athlete at time (t) is...

An endurance training runner begins at point A and races to point B, then switches and races again to point A, then switches and races again to point B. The position for the athlete at time (t) is given by: s(t)=t^3-6t^2+9t-2 a) On which intervals is the velocity positive? In which direction is the runner running during these intervals? b) On which intervals is the velocity negative? In which direction is the runner running during these time intervals? c) At which point is velocity zero? What is the runner’s movement at these points?