# Trig

posted by
**Matt**
.

I'm really having a hard time determining an equation for a pendulum problem. It has to be in the form H(t)=asin[b(t-c)]=d. I've already determined a=25, d=30 and b=pi/14 but I can't figure out how to get c (the phase shift). How do I figure out the phase shift in these type of problems? Thanks!!!