Mathematical function parameters

Question

Hello
I tried to build an application (in the C# console application) that show me the cut function (I don't know how you say it in english, I mean that if I have function f(x)=2x^2, than f'(x)=4x)
I failed in doing it because I can't think how to do it with parameters
So my question is:
C# has parameters for mathemtical functions?
And if it's true, how to use it?