# How do you find the rectangular coordinates of the point with polar coordinates (3,pi)?

Since $\left(x , y\right) = \left(r \cos \theta , r \sin \theta\right)$,
$\left(x , y\right) = \left(3 \cos \left(\pi\right) , 3 \sin \left(\pi\right)\right) = \left(- 3 , 0\right)$