13.5.2
The solution of the differential equation of damped oscillations of a material point has the form x = e-0.5t (C1 cos 3t + C2 sin 3t). Determine the integration constant C2 if the integration constant C1 = 1.5 and at the instant t0 = 0 the velocity of the point v0 = 0. (Answer 0.25)