Question

What is the Cartesian form of `(9,(3pi )/4)`?

Answer 1

The Cartesian form of `(r,theta)=(9,(3pi)/4)` is `(x,y)=(-(9sqrt(2))/2,(9sqrt(2))/2)`.

Explanation:

Use the equations `x=rcos(theta)` and `y=rsin(theta)` to get `x=9cos((3pi)/4)=9 * -(sqrt(2))/2=-(9sqrt(2))/2` and `y=9sin((3pi)/4)=9 * (sqrt(2))/2=(9sqrt(2))/2`.