[Ideas] Math Multi-Tool

I'm making a math multi-tool and I need some ideas, like equations and stuff like that. I have areas, volumes, and a basic calculator on it and it seems like it needs more. Any ideas would be helpful. I'm mainly doing to get used to VS 2010.

Factorization

This.

f(a+h) - f(a)
___________ > You just gotta enter f, meaning you can enter a function for f.
h

Then people should be able to choose how many numbers should be displayed for a and in which step each...in a listbox..

Like it'd say...

f(x) = x²

A | Result

1 result here
2 etc
3 etc

> 1er steps

This would prolly look like this...

((F(A+h)-F(a))/h

You won't get me =/

nevermind <.<

Make it do my precal hw :P