Answer
$$(-4,0)$$
Work Step by Step
$$\eqalign{ & \left( {4,5\pi } \right) \Rightarrow r = 4{\text{ and }}\theta = 5\pi \cr & {\text{Converting to cartesian coordinates }}\left( {x,y} \right).{\text{ Where}} \cr & x = r\cos \theta {\text{ and }}y = r\sin \theta \cr & {\text{We obtain}}{\text{,}} \cr & x = 4\cos \left( {5\pi } \right) = 4\left( { - 1} \right) = - 4 \cr & y = 4\sin \left( {5\pi } \right) = 2\left( 0 \right) = 0 \cr & {\text{The cartesian coordinates are:}} \cr & x = - 4{\text{ and }}y = 0 \cr \cr} $$
