# What is the Cartesian form of (-2,(81pi) /16)?

Apr 29, 2017

$\approx \left(1.96 , 0.39\right)$

#### Explanation:

Given: $\left(- 2 , \frac{81 \pi}{16}\right) = \left(r , \theta\right)$

To convert to Cartesian form $\left(r \cos \theta , r \sin \theta\right)$

$- 2 \cos \frac{81 \pi}{16} \approx 1.961570561$
$- 2 \sin \frac{8 a \pi}{16} \approx .390180644$
$\approx \left(1.96 , 0.39\right)$