Derivative Calculator

I have seen some applications around the internet where you can enter a string of characters and it will find the derivative equation for you.
Do these use the basic method of chain-rules, power-rules and such? Or is there a differnt method to differntiate for when using computers?

I am looking to make a derivative calc in VB.NET, and I am wondering how I should start off. I was thinking to make it work just like an equation-parser and break the equations down into simple strings and execute the differention steps...?

Thank You

To my knowledge, yes, all they do is to parse the formula and attempt to "act human" when solving algebraically. If you're talking about finding the numerical value of the derivative at a particular point (f'(a) instead of f'(x)), then there are other methods, but finding the general derivative of an equation involves the algebra that we all use and love :)

Hope that helps

I was just hopping there would be an easier way.....
Any suggestions of a good parse methods or anyone want to help???