Answer
$(7.62, 336.8^\circ)$
Work Step by Step
To convert from polar to rectangular coordinates we use $x=r\cos\theta$ and $y=r\sin\theta$. To convert from rectangular to polar coordinates, we use $r=\pm\sqrt{x^2+y^2}$, $\tan\theta=\frac{y}{x}$, but aware of which quadrant the point lies in.
Hence here the given point in polar coordinates using a graphing calculator: $(\pm(\sqrt{(7)^2+(-3)^2},\tan^{-1}\frac{-3}{7})=(7.62, 336.8^\circ)$
