12. The acceleration of a moving object is given as a(t) =2t -6 . Make sure to show all the details in your calculation. ( 8 pts.) a. Find the velocity function v(t) if v(0) =5. b. Find the displacement function s(t) if s(0) =1. c. When will the velocity equal zero? d. What is the displacement in the interval 0 St $9. 13. Evaluate the integral |3xx by using the Right Riemann Sum. Be sure you show all the steps. Make sure to show all the details in your calculation. (4 pts.) n(n +1) You may need the summation formulas Sk = and /or c = cn *=1 2 K=1