# What is the Cartesian form of (-7,(11pi)/8)?

Mar 20, 2016

Cartesian form of coordinates are $\left(2.6789 , 6.4673\right)$

#### Explanation:

Cartesian form of $\left(r , \theta\right)$ is $\left(r \cos \theta , r \sin \theta\right)$

Hence for $\left(- 7 , 11 \frac{\pi}{8}\right)$, it will be

$\left(- 7 \cos \left(11 \frac{\pi}{8}\right) , - 7 \sin \left(11 \frac{\pi}{8}\right)\right)$

As $\cos \left(11 \frac{\pi}{8}\right) = - 0.3827$ and $\sin \left(11 \frac{\pi}{8}\right) = - 0.9239$

Hence cartesian form of coordinates are $\left(2.6789 , 6.4673\right)$