Love the slider bars. They really show how the graph changes for each parameter. Checked against a few quadratics and it appears to be working fine.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Woah that is cool!!
I would love you if you created a function grapher, you know, graphing y=x y=e^x .....