# How do you use the definition of the derivative?

##### 1 Answer

Apr 19, 2017

The definition of the derivative may be of help. For instance:

**Prove that the derivative of #f(x) = x^2 - 1# is #f'(x) = 2x#**

By the definition of the derivative.

Which is what we needed to show.

**Practice exercises**

Hopefully this helps, and good luck!