# Secant and Tangent Lines

- Author:
- Michelle Krummel

Investigate the relationship between the secant line (green) and tangent line (pink) as the value of h approaches 0.

1. Write an expression to represent the horizontal distance between points P and Q.
2. Write an expression to represent the vertical distance between points P and Q.
3. Write an expression to represent the slope of the secant line passing through points P and Q.
4. As h approaches zero, what do you notice about the slope of the secant line (in comparison to the tangent line)?
5. Change the input function f(x). Does the same apply?
6. Write a limit statement showing what you've learned.