Generation of differential constant

[soopo]

Homework Statement

What is the name of the following very small unit?

$${f}'(x) h$$

The Attempt at a Solution

I know the name in Finnish "Differentiaalikehitelma", but not in English.
However, I have not managed to find help about the method which my professor says is very important.

My suggestion for the name is "generation of differential constant".
However, I have not managed to find any help concerning the unit.

 

[foxjwill]

I think what you're talking about is

$$df = \frac{df}{dx}dx= f'(x) dx.$$​

If that is what you're talking about, then we'd call a "differential form".

 

[soopo]

I think what you're talking about is

$$df = \frac{df}{dx}dx= f'(x) dx.$$​

If that is what you're talking about, then we'd call a "differential form".

Your equation makes sense.
What is the name of it?

 

[foxjwill]

Your equation makes sense.
What is the name of it?

The differential of f.