# What is the Cartesian form of (-13,(5pi)/16))?

Polar form $\left(r , \theta\right) = \left(- 13 , \frac{5 \pi}{16}\right)$
$r = - 13$ and $\theta = \frac{5 \pi}{12}$
$x = r \cos \theta$ and $y = r \sin \theta$
$x = r \cos \theta = - 13 \cos \left(\frac{5 \pi}{12}\right)$
$y = r \sin \theta = - 13 \sin \left(\frac{5 \pi}{12}\right)$