Any ideas on how to solve the following equation?
dx/dt = k + qcos(x)
where k and q are constants
My main problem is that the cos is a function of x, not t.
Try bringing the dt over to the right side, and the quantity (k + qcos(x)) to the other. Then integrate from there (it might be easier to split 1/(k + qcos(x)) into partial fractions).
… There may be an easier way, though, I’ll try to look through my old papers and see if I can recall any tricks. The summer made my brain a bit fuzzy… 
Wow, I feel stupid. I can’t believe that I didn’t see that. But anyway, the resulting solution is fairly nasty.
Thanks.