1. 8 – 5 Properties of Logarithms Day 2
Objective: Be able to use the properties of logarithms to solve real life problems.
Change of base formula

2. Change of Base Formula

3. Example 4: Using the change of base formula

4. Using Common Logarithms:

5. Using Natural Logarithms

6. Example 5: Using Logarithmic Properties in Real Life
An ordinary annuity is an account in which you make a fixed deposit at the end of each compounding period. You want to use the annuity to help you save for college. The formula

7. gives the time t (in years) required to save S dollars in the annuity if your periodic payments P (in dollars) are made n times a year and the annual interest rate is r (in decimal form).

8. a. Expand the right side of the equation

9. b. How long will it take you to save $20,000 in annuity that earns an annual interest rate of 5% if you make a monthly payment of $50?

10. 8 – 5 day 2 Home work page 497
56 – 84 even