Nice but can be improve
It is pretty simple to create a program that can solve something for the formulas. I know cause I create one for my graphing calculator when I was in high school. so I might not have taken much time to create it into a simple flash.
If you want to improve it though, you can take out the one for the circle since an ellipse is basically the same as a circle, but with the radii being the same. speaking of the circle, that part of the program doesn't work at all.
In conclusion it is a nice tool to use, however it still has room for improvement.