>>13470305More on that before I accept any thanks. So you get this kind of stuff, and those would give you then the bottom left corner equation which you can use to find the focus points of your ellipses. Every time, assume your ellipse's centre is in the origin and then just set x=0 to get the corresponding points. I forgot that those axes were supposed to be like the radius and not the diameter of a circle, so that's why there is division by 4... Sorry about that. I hope I made no mistakses!
