1. 3.3 Interpret Rates of Change of Quadratic Functions p. 69

2. Vocabulary
rate of change: the speed at which a variable changes over a specific period of time Ex:Cell Phones ( cost per ______) Cars (miles per ______) Filling a shark tank (liters per _____) In a graph…….This is known as SLOPE

3. GOAL
Use intervals of increase and decrease to understand average rates of change of quadratic functions.

4. Intervals of Increase
Functions are continuous from left to right, if from left to right the function is going up, the function is increasing.
Intervals of Decrease
Functions are continuous from left to right, if from left to right the function is going down, the function is decreasing.

5. Polynomial Functions and Their Graphs
Local Maximum
Increasing Function
Decreasing Function
Local Minimum

6. Ex. 1: Identify Intervals of Increase & Decrease
Graph the function. Identify the intervals over which the graph increases and decreases.
a) y = -x2 – 6x – 4

7. Guided Practice p. 69 #1, 2, 4, 6

8. Ex. 2: Calculate an Average Rate of Change
Calculate the average rate of change of the function y = -0.5x2 + 4 on the given interval.
a) b)

9. Ex. 2: Calculate an Average Rate of Change
Calculate the average rate of change of the function y = -0.5x2 + 4 on the given interval. c)

10. Guided Practice p. 70 #7

11. Ex. 3: Compare Average Rates of Change
Compare the average rates of change of y = x2 and y = x on

12. Guided Practice p. 71 #10

13. Homework
Pg. 72, 1 – 15 all Pg. 73, 1 – 7 all Take Home Quiz 3.1 – 3.2