Answer
$\sin (-900)^{\circ}=0$
Work Step by Step
1. What we know about -900 degree angle
$\theta=180^{\circ}$ (because it is a co-terminal angle and values of x and y will be the same)
$x=-1$
$y=0$
$r=1$
2. Substitute in:
$\sin\theta=\frac{y}{r}=\frac{0}{1}=-0$
