# What is the Cartesian form of ( -8, (25pi)/8 ) ?

$\left(7.39 , 3.06\right)$
$x = r \cos \theta$ = $- 8 \cos \left(\frac{25 \pi}{8}\right) \approx 7.39$
$y = r \sin \theta = - 8 \sin \left(\frac{25 \pi}{8}\right) \approx 3.06$