1. Goal 4.04: Exponential Functions

2. Exponential Growth and Decay

3. Exponential Growth Growth factor: b > 1 Divide by 100, then Add 1 4% compounded annually 12.3% monthly increase

4. Exponential Decay Growth factor: b < 1 Divide by 100, then SUBTRACT from 1 4% annual decrease Taxed at 6.7% per year

5. Examples An endangered tiger population of 120,000 decreases by 7% each year. If we do nothing to change the situation, how many tigers will be left after 5 years? Is this growth or decay? How do we solve?

6. Examples There are 400 rabbits in a lab. Due to reproduction, they triple every 2 months. How many will there be after 3 years?

7. Examples A $38,000 SUV depreciates by 18.5% every year. How much would it be worth after 10 years?

8. Examples Craig bought a utility trailer in 2007 for $2500. The trailer depreciates 7% each year. What is the difference in the trailer’s value of between the years 2011 and 2013?

9. You Try… 1. Jamar is breeding hopping ants in an ant farm. Hopping ants quadruple every 3 months. If Jamar initially had 10 ants, how many did he have after 3 years?

10. You Try… 2. The swine flu virus tripled in the number of infected patients every week. If there were only 7 people infected on May 1st, how many people in the US had the virus by June 1st? (Hint: Assume there are 4 weeks in a month) 3. Is the equation exponential growth or decay?