How do I convert from 3-D Cartesian coordinates to cylindrical coordinates?

1 Answer
Oct 21, 2014

If Cartesian coordinates are (x,y,z), then its corresponding cylindrical coordinates (r,theta,z) can be found by

r=sqrt{x^2+y^2}

theta={(tan^{-1}(y/x)" if "x>0),(pi/2" if "x=0 " and " y>0),(-pi/2" if " x=0" and "y<0),(tan^{-1}(y/x)+pi" if "x<0):}

z=z

Note: It is probably much easier to find theta by find the angle between the positive x-axis and the vector (x,y) graphically.


I hope that this was helpful.