## Trigonometry 7th Edition

$\sin(-\theta)\sec(-\theta)\cot(-\theta)=1$
$\sec(-\theta)$ can be written as $\frac{1}{\cos(-\theta)}$ $\cot(-\theta)$ can also be written as $\frac{\cos(-\theta)}{\sin(-\theta)}$. As such, $\sin(-\theta)\sec(-\theta)\cot(-\theta)=\sin(-\theta)\frac{1}{\cos(-\theta)}\frac{\cos(-\theta)}{\sin(-\theta)}=1$. The trigonometric terms in the equation cancel out, therefore, $\sin(-\theta)\sec(-\theta)\cot(-\theta)=1$.