# How do you find the formula for the derivative of #1/x#?

##### 2 Answers

Apr 14, 2015

Therefore

Apr 14, 2015

I will assume that you are working from first principles, that is the definition.

There are two choices for how to "officially" define the derivative, every textbook author and teacher makes a decision which one to make official.

I'll use:

For

That is: