2 Jan 15:49 2005

### Defining derivative functions.

edA-qa mort-ora-y <eda-qa <at> disemia.com>

2005-01-02 14:49:41 GMT

2005-01-02 14:49:41 GMT

I need a way to define a function and its derivative as functions. That is, I want to accomplish what one might expect the following would do: f(x) := q*x^2 + r; df(x) := diff( f('x), 'x ); But if you do this the x variable in df(x) is in no way related to the x variable in f(x). If you try this: df(x) := diff( f(x), x ); It fails as obviously you are differentiating with whatever is passed to df(x), not the symbolic variable x anymore. I even tried using an intermediary: eq : q*x^2 + r; f(x) := eq; df(x) := diff( eq, 'x ); But this also didn't work. So, how do I do this, that is, create a function and then create its derivative (also as a function). -- -- edA-qa mort-ora-y Idea Architect http://disemia.com/(Continue reading)