9. (5%) An undamped string/mass system, in which the mass m = 1 slug and the spring constantk = 10 lb/t, is driven by the 2-periodic external force F(t) = 1-t,0 <t<2; f(t+2) = f(t).Assume that when f(t) is extended to the negative t-axis in a periodic manner, the resulting function is odd.Find a particular solution Xp(t).
