# Handle variable name

Dear all,

I would like to pass a function as a parameter and also one of its variable. The simplest situation would just to evaluate a function f.

```
def test(f,myvar,myval):
return f(myvar=myval)
f = x^2
print(test(f,x,3)
```

It returns `x^2`

, but I would like `9`

. Of course I don't know a priori what would be the name of the variable and f may have several variables.

The long question is that I would like to define something that `plot(f,(x,xmin,xmax))`

. Is there's a standard way to handle this triple `(x,xmin,xmax)`

? Is there's a web page for the source code for such functions to study the standard implementation?

Thanks a lot! Arnaud