1. Section 12.3

2. The Tangent Line Problem
When you find the derivative you are finding the slope of the graph.
Formula for the derivative of a function:

3. The Tangent Line Problem
Steps for using the formula to find the derivative:
Plug in x + h for every x in the function.
Subtract the function
Simplify the numerator.
Factor an h out of what you have left in the numerator.

4. The Tangent Line Problem
Steps for using the formula for finding the derivative: (continued)
Cancel the h you factored out with the h in the denominator.
Plug in zero for any remaining h’s.
Simplify your answer.
If you are given an ordered pair, plug in the x-value for any x’s you still have.