[groanup]

You seem to be in the business Why don't you explain it

I'm not in the business. I used to be and it has changed a hell of a lot since then.

I'm not in the habit of explaining posts to those who post them.

I'll assume that your answer means that you don't have any idea what a derivative is but that you are trying to explain it to someone else anyway.

[dennisw]

LOL
I knew you would not elaborate or explain it better.