Answer
$-2$
Work Step by Step
Our aim is to solve the integral $\int_{-\pi}^{0} \sin x \ dx$
Therefore,
$\int_{-\pi}^{0} \sin x \ dx=[-\cos x]_{-\pi}^{0}$
Now, $[-\cos x]_{-\pi}^{0}=-[\cos 0-\cos (-\pi)]$
or, $= -[1-(-1)]$
or, $=-2$