Answer
$\sin\theta=\frac{y}{r}=\frac{-1}{1}=-1$
$\cos\theta=\frac{x}{r}=\frac{0}{1}=0$
$\csc\theta=\frac{r}{y}=\frac{1}{-1}=-1$
$\sec\theta=\frac{r}{x}=\frac{1}{0}=undefined$
$\tan\theta=\frac{y}{x}=\frac{-1}{0}=undefined$
$\cot\theta=\frac{x}{y}=\frac{0}{-1}=0$
Work Step by Step
$\theta=-90^{\circ}; x= 0; y=-1$
$r=\sqrt {(x)^{2}+(y)^{2}}= \sqrt {(-1)^{2}+(0)^{2}}=\sqrt {1}=1$