# What is the Cartesian form of (-12,(-21pi) /16)?

Apr 16, 2017

$\left(6.667 , - 9.978\right)$

#### Explanation:

Use the parametric form to find the $x$ value and $y$ value.

$x = r \cos \theta$

$y = r \sin \theta$

Solve for $x$ first:

$x = - 12 \cos \left(- 21 \frac{\pi}{16}\right) \approx 6.667$

Solve for $y$:

y=-12sin(-21ou/16~~-9.978

Put this all together to get the cartesian form:

$\left(6.667 , - 9.978\right)$