1. TODAY IN ALGEBRA…  Warm up: Sequences  Learning Target 1: 8.6 You will write and graph exponential decay functions.  Learning Target 2: You will use what you understand about exponential functions to find geometric sequences  Independent Practice/HW #4 Due Today  CH. 8 TEST FRIDAY!

2. WARM UP: Complete the Arithmetic and Geometric sequences half sheet. We will go over the solutions as a class. 42 86 42 86

3. 8.6 EXPONENTIAL DECAY FUNCTIONS x-2012 y Check to make sure that the x’s are increasing by 1. Find what number the previous term is MULTIPLIED by to get the next term. This will be b in your equation. This will be a in your equation.

4. 8.6 EXPONENTIAL DECAY FUNCTIONS x-2012 y Check to make sure that the x’s are increasing by 1. Find what number the previous term is MULTIPLIED by to get the next term. This will be b in your equation. This will be a in your equation.

5. 8.6 EXPONENTIAL DECAY FUNCTIONS 1. Make a table. 2. Graph the points. Domain: All real numbers Range: All numbers greater than zero.

6. 8.6 EXPONENTIAL DECAY FUNCTIONS 1. Make a table. 2. Graph the points. Domain: All real numbers Range: All numbers greater than zero.

7. 8.6 EXPONENTIAL DECAY FUNCTIONS

8. 8.5 EXPONENTIAL GROWTH FUNCTIONS

9. 8.6 EXPONENTIAL DECAY FUNCTIONS Initial amount Decay rate Time period Decay factor

10. 8.5 EXPONENTIAL GROWTH FUNCTIONS EXAMPLE: The number of acres of Ponderosa pine forests decreased in the western US from 1963 to 2002 by 0.5% annually. In 1963 there were about 41 million acres of Ponderosa pine forests. *Must write the rate as a decimal! t=After 39 years In millions

11. 8.5 EXPONENTIAL GROWTH FUNCTIONS COMPOUND INTEREST: A farmer bought a tractor in 1999 for $30,000. The value of the tractor has been decreasing at a rate of 18% per year. What was the approximate value of the tractor in 2005? *Must write the rate as a decimal!

12. HOMEWORK #5: Pg. 535: 3-6, 10, 14, 20, 24, 28, 32-34, 47-49 If finished, work on other assignments: HW #1: Pg. 492: 4-48 even HW #2: Pg. 498: 4-44 even HW #3: Pg. 506: 4-44 even In Class Work: Scientific Notation HW #4: 523: 3-7, 10, 14, 18, 22, 24, 28, 30, 38-40