(a)
Let $I = \int_{}^{}{\frac{e^{x}(1 + \sin x)}{1 + \cos x}dx}$
$= \int_{}^{}\frac{1}{2}e^{x}\sec^{2}\frac{x}{2}dx + \int_{}^{}e^{x}\tan\frac{x}{2}dx$
$= \frac{1}{2}\left\lbrack 2e^{x}\tan{\frac{x}{2} - \int_{}^{}{2e^{x}}}\tan\frac{x}{2}dx \right\rbrack + \int_{}^{}e^{x}\tan\frac{x}{2}dx$
$= e^{x}\tan\frac{x}{2} + c$