Please solve the following

MTH 31 (11) A particle is moving along a horizontal straight line. Its position, s(t), velocity, v(t), and acceleration, a(t), for t 2 0 are as follows: goldong to nohillon a at work s(t) = +3 - 6+2 - 15t, v(t) = 3t2 - 12t - 15, a(t) = 6t - 12. Determine the time intervals, if any, during which the object is moving left. (12) Find the number(s) at which f is discontinuous. Explain your answer. (i() x 0 and f(3)