How can we find eccentricity of a Conic Section?

Check out a href="http://mathworld.wolfram.com/ConicSection.html" rel="nofollow"http://mathworld.wolfram.com/ConicSectio…/a especially equation (1). I think that almost does it for you. In terms of your equation, it looks like a/b may be = 1-e^2. I'm not sure if that holds if h>0. I don't know how much that messes things up.