# What is the Cartesian form of (18,(-51pi)/8))?

Jul 7, 2017

$\left(6.888 , - 16.630\right)$

#### Explanation:

We're asked to find the Cartesian (rectangular) form of a polar coordinate.

To do this, we can use the equations

$x = r \cos \theta$

$y = r \sin \theta$

So

x = 18cos((-51pi)/8) = color(red)(6.888

y = 18sin((-51pi)/8) = color(blue)(-16.630

The rectangular form is thus

$\left(\textcolor{red}{6.888} , \textcolor{b l u e}{- 16.630}\right)$