>Trying to pull from memory here. You have the equations for your two ellipses. Don't you just set those two equations equal to each other & solve for possible values of x & y? I found some long winded explanations by googling on "equation for where ellipses intersect", but didn't read into the specifics.

I saw those also. I ran a SIN on the "radius" and got an x,y at the "angle" of the intersect off the center. It was close for some fooling i did. But SIN, i think, is a "circle" function - and this is an elipse. I can express the elipse as a "disc" that is off "plane" (not flat). I have that value. That parallelogram inversion cr_pola is funky - if you read it real good you can see the write miised a description. He was showing a circle over an elipse and indicated "the diameter was the same as the diameter" - huh and double huh.

There's some simple pathagoreum function. Is the SIN of an elipse the same as a circle - that is the question. They look close with a rough plot - we'll see.