}
, 
, 
, 
We discard the second answer since the sine can only be
between -1 and +1.
Use the inverse sine function to get the value for q.
I'll let you finish, since you did not specify whether you want
degrees or radians, or whether you only want answers between 0°
and 360°, or between 0 an 2p or whether you wanted a general
solution in terms of an arbitrary integer n.
Edwin
