# What is the Cartesian form of ( -3 , (25pi)/12 ) ?

Jul 27, 2018

$\left(0 , - 3\right)$

#### Explanation:

$x = r \cos \theta = - 3 \cos \left(\frac{25 \pi}{2}\right) = - 3 \cos \left(\frac{\pi}{2} + 12 \pi\right)$

$= - 3 \cos \left(\frac{\pi}{2}\right) = 0$

$y = r \sin \theta = - 3 \sin \left(\frac{25 \pi}{2}\right) = - 3 \sin \left(\frac{\pi}{2} + 12 \pi\right)$

$= - 3 \sin \left(\frac{\pi}{2}\right) = - 3$

Hence the Cartesian form of $\left(- 3 , \frac{25 \pi}{12}\right)$ is $\left(0 , - 3\right)$.