# Derivative of a Product

- Author:
- Tim Brzezinski

- Topic:
- Derivative

Provided the described limits exist, we've already discovered that
1) The derivative of a sum of two functions = the sum of the derivatives of these functions.
2) The derivative of a difference of two functions = the difference of the derivatives of these functions.
Yet what about replacing the word "sum" or "difference" with the word "product"?

**That is, is the derivative of the product of two functions evaluated at any input = the product of the derivatives of these two functions (evaluated at this same input)?**Interact with the applet below for a minute. Study it carefully. Move any 1 of the white points around if you need to.**Then answer the question in pink.**