The oscillations produced by a block of mass m attached to a spring of elastic constant k immersed in a container with a heavy oil inside is given by the

y(t) = 2 (e^-3t) cos (9t) + 4 (e^-3t) sin (9t)

Determine:
a) The amplitude of the oscillations
b) The phase constant 
c) The damper factor
d) The pseudo frequency