(2) In R, A point mass M moves with the velocity v (t) = (1, t cost, tsin t) and the original position r(0)= (-1,1,0). Another point mass M has the position function r(t) = (t, 2 cost, 2 sin t). (a) Compute ri(t), the position function of M. (b) Denote L1(s) and L2(s) be the distance traveled by M and M from t = 0 tot = s respectively. Find L2 (2019)/L (2019).