1. Warm up
Write an exponential function that has a start value of 6 and a common ratio of -3.
2. For a school project you were given $500 and were told to find out how many people you could help if you gave away half your money each week.
Write an equation for the school project.
How long will it take for you to have less than $1?

2. Questions over HW?

3. Geometric Sequence
A sequence of terms that have a common ratio between them

4. Explicit Formula
Formula used to find the nth term of a sequence

5. Explicit Formula for Geometric Sequence
Where a1 is the first term in the sequence and
r is the common ratio

6. Recursive Formula for Geometric Sequence
Where a1 is the first term in the sequence and
r is the common ratio

7. Geometric Sequence
Example 1: Find the common ratio
r = 2

8. r = 1/4 Geometric Sequence Example 2 : Find the common ratio
256, 64, 16, 4, …
r = 1/4

9. Example 3: Find the common ratio, the explicit formula, and the seventh term.
6, 3, 1.5, 0.75 …

10. Example 4: Find the common ratio, the explicit formula, and the tenth term.
-4, -12, -36, -108 …

11. Example 5 : The fifth term is 1,792. The common ratio is 4
Example 5 : The fifth term is 1,792. The common ratio is 4. Write the explicit formula.

12. Example 6 : During the month of October, a few teachers decided to spread some holiday fun by starting a game of getting “boo”ed. On the first day, 3 teachers were given “boo” bags and directions to “boo” 2 other teachers. If every teacher followed the directions to “boo” 2 teachers with candy and a sign, find the following:
a. The explicit formula b. The first 4 terms
3, 6, 12, 24…

13. Homework
Sequence Practice WS