# What is the Cartesian form of (18,(-11pi)/8))?

Mar 4, 2016

(-6.888 , 16.63 )

#### Explanation:

Using the formulae that links Polar to Cartesian coordinates.

• x = rcostheta

• y = rsintheta

here r = 18 and $\theta = \frac{- 11 \pi}{8}$

 x = 18cos((-11pi)/8) ≈ -6.888

 y = 18sin((-11pi)/8) ≈ 16.63