Evaluate : `int1/(1+cos x)dx`

Explanation

` int frac{1}{1+cos x} dx`


`=int frac{1}{2 cos ^{2}(frac{x}{2})} dx`


`=frac{1}{2} int sec ^{2}(frac{x}{2}) d x`


` =frac{1}{2}[frac{tan (frac{x}{2})}{frac{1}{2}}]+{c} `


`=tan (frac{x}{2})+{c}`