Polar Coordinates

#Math
3D version is cylindrical coordinates

$\displaystyle (x,y)=(r\cos \theta,r\sin \theta)$

• Conversion from polar coordinates to rectangular coordinates

$\displaystyle (r,\theta)=\left( \sqrt{ x^{2}+y^{2} },\tan ^{-1}\left( \frac{y}{x} \right)\right)$

• Conversion from rectangular to polar coordinates

$\displaystyle J_{\text{polar}}=J_{\text{cylindrical}}=r$