How to evaluate $\int \frac {dx}{\cos x+C}$? I want to evaluate  -

$$\int \frac {dx}{\cos x+C}$$

Where $C$ is an arbitrary constant.I tried substitution and parts but could not do it.
Note that for $C=1$ one can simply do this by using compound angle formulas.But what about other values of $C $?
Thanks for any help!!

Hint: use the substitution $t=\tan{\frac{1}{2}x}$. Then $dx = 2dt/(1+t^2)$, 
$$ \cos{x} = \frac{1-t^2}{1+t^2}, $$
and the integral reduces to that of a fairly simple rational function.
