Solve for $\theta$: $a = b\tan\theta - \frac{c}{\cos\theta}$ This question was initially posted on SO (Link).  I'm not sure the answer given there was correct.  I cannot get the results from those expressions to match my CAD model.
The title pretty much sums it up. How do I solve for theta given the following equation.
$$a = b\tan\theta - \frac{c}{\cos\theta}$$
I am not a student and this is not homework. It's been quite a while since I've done any significant trig and I'm out of time to figure this out.

The given equation is equivalent to
$$
b\sin(\theta)-a\cos(\theta)=c.
$$
