Plotting a C function

ROOT
1

Hi
i want to plot a function defined in a c file

first i call the file by .L
and after i try to plot , in a similar way that in the example of the doc
TF1 f1(…)
but it dont work

how must i do

P.S.
sorry for my easy question i just starting using root

2

I think you shoud post a little working example showing your problem.