Classical Mechanics - Special Interest Problem

For the underdamped case of the harmonic oscillator with viscous damping, the general solution derived in class was

x(t) = e-bt ( A1eiwt + A2e-iwt )

Using the identity eiq = cosq + i sinq, show that x(t) can be written as

x(t) = e-bt ( B cos wt + C sin wt )

= D e-bt cos(wt - j )

Where the intermediate step is shown as a hint on how to proceed. Show explicitly how D and j are related to A1 and A2. Note that in order for B, C, D and j to be real, both A1 and A2 must generally be complex.


Hardcopy entries should be submitted in class by noon on Monday of next week. Answers should be concise but complete.