Hello there,

I would like to do this:

let f(x) = 0.25*x^2 and plot it;
let g(x) = f'(x);
let h(x,k) = f(k) + g(k) * (x-k) and plot it;

This should plot the f function and its tangent line h in function of k, shouldn't it?
The problem is that I cannot define g as the derivative of f. Of course i don't need to plot it, i need its expression.

How can this be done?

Thanks a lot!!

In which application are you trying to accomplish this?

Oh, i'm really sorry for that, i totally forgot.

I'm using KMPlot on Lubuntu =)

I'm really sorry, I'm a new Linux user and I loved that application so I downloaded it from the download center.. =P

Thanks a lot! Hope I didn't miss anything now!

Unfortunately i'm afraid that KMPlot is minimally maintained at this time - and i'm unfamiliar with the application. You may wish to try LabPlot2 which is a similar KDE/Qt application I believe, which is actively maintained and similar in feature set.

Ok, I'll check it out!


Thanks a lot!!!

Oh, wait a second, is it compatible with Lubuntu?

It should be as far as I am aware - much like other applications, it shouldn't be dependent on the desktop environment it is run in.