Question

A guitar string is pulled at point P a distance of 3cm above its rest position. It is then released and vibrates in damped harmonic motion V(t)= ke^(-ct) Cos(wt) with a frequency of 2 cycles per second. After 2 seconds, it is observed that the amplitudes of the vibration at the point P is 1cm.
1) find K and W.
2)find the damping constant C.