Answer
$\csc(-450)^{\circ}=-1$
Work Step by Step
1. What we know about -450 degree angle
$\theta=270^{\circ}$ (because it is a co-terminal angle and values of x and y will be the same)
$x=0$
$y=-1$
$r=1$
2. Substitute in:
$\csc\theta=\frac{r}{y}=\frac{1}{-1}=-1$