TODAY IN ALGEBRA 2.0…  WARM UP: Write and solve equations using exponential GROWTH  Learning Target 1: 7.2 You will write and solve equations using exponential DECAY  Independent Practice

7.2 EXPONENTIAL GROWTH and DECAY COMPARISON PARENT EQUATION:

7.2 EXPONENTIAL DECAY EXPONENTIAL DECAY MODEL: EXAMPLE: A new snowmobile costs $4200. The value of the snowmobile decreases by 10% each year. Write an exponential decay model giving the snowmobile’s value after (t) years. Estimate the value after 3 years.

7.2 EXPONENTIAL DECAY: PRACTICE The value of a snowmobile has been decreasing by 7% each year since it was new. If the snowmobile was bought for $5200, what would the value be in 3 years?

7.2 EXPONENTIAL DECAY: EXAMPLE The number of acres of Ponderosa pine forests decreased in the western United States from 1963 to 2002 by 0.5% annually. In 1963 there was about 41 million acres of Ponderosa pine forests. a. Write a function that models the number of acres of Ponderosa pine forests over time t. b. To the nearest tenth, about how many million acres of Ponderosa pine forests were there in 2002?

7.2 EXPONENTIAL DECAY: PRACTICE You buy a new personal computer for $1600. It is estimated that the computer’s value will decrease by 50% each year. a. Write a function that models the value of your computer over time t. b. About how much would your computer be worth in 4 years?

HOMEWORK #2: Pg. 489: 1, 26, 30, 31, 33 If finished, work on other assignments: HW #1: Pg. 483: 28-30, 37, 38 Pg. 543: 27, 28