Well, it is not really hard to convert them. My main problem is thinking in Polar coordinates. Cartesian coordinates are really easy to think about for me (after how many years of experience) but then I get to Calc 3 and I hit a brick wall. Does anyone have some insight on how to get past this problem? Thanks in advance! -Jeremy i.e. x^2 + y^2 = 9 gives a cylinder of radius 3 in 3-D the same equation is r = 3, right? That's pretty simple, but once it gets more complicated Boom, I'm lost.