hey buddy use this rule
f'(x)/f(x) = ln{f(x)}
here ill show u the steps..
S sinx/1+ cos x
we can see that 1+cosx when you find d/dx it gives us -sinx
therefore
-S - sinx/1+cosx follows that rule i just gave you...
= -ln(1+cosx )
there is another way where you can use t formula where tan a/2 = t but this is alot longer but very effective in areas such as
S 1/sinx+cosx dx