Conic Sections at Mac App Store analyse

Theres a good variety here in how to look at conic sections -- as sections of a cone, with the usual coordinates, with matrices, in general polynomial form, in polar coordinates, and so on. Theres also a lot of "guts" showing: some of the graphics like the ones at the top here come with equations, and some of those equations would be pretty tough to explain in a classroom! On the other hand, some kids might get motivated to learn some math to understand how to make pretty pictures like these for themselves. Theres a lot of simplifying that could be done, perhaps. For example, it would be nice if the x, y coordinates could be related to the x,y coordinates in some way without having to repeat the formulas in multiple places, to make the relationship more explicit and clear.