Question

Integrate the function $\frac{\sin x}{1+\cos x}$

Answer 1

Let $1+\cos x=t$
$\therefore -\sin xdx=dt$
$\Rightarrow \int \frac{\sin x}{1+\cos x}dx=\int -\frac{dt}{t}$
$=-\log |t|+C$
$=-\log |1+\cos x|+C$