2. + Lesson 3B: Geometric Sequences

3. + Ex 1: Can you find a pattern and use it to guess the next term? A) 3, 9, 27, … B) 28, 14, 7, 3.5,... C) 1, 4, 9, 16,...

4. + Definition: An geometric sequence is a sequence made by multiplying or dividing the same value each time.

5. + Explicit Formula a, ar, ar 2, ar 3 … r = common ratio a = 1st term n th term:

6. + Ex 2: Find a, r, and the nth term. Or state that the sequence is not geometric. A) 1, ½, ¼, … B) 28, 14, 7, 3.5,... C) 1, 4, 9, 16,...

7. + Find the first 5 terms and the n th term: a = -3 & r = 5 Ex 3:

8. + Find the 8 th term: 5, 15, 45 … Ex 4:

9. + Ex 5: The formula describes a geometric sequence. What are the first 5 terms in the sequence?

10. + Recursive Formula

11. + Ex 6: Write a recursive formula for the following sequence: 300, 30, 3, 0.3,…

12. + Cool Math! https://www.youtube.com/watch?v=wTlw7fNcO-0 https://www.youtube.com/watch?v=SjSHVDfXHQ4 https://www.youtube.com/watch?v=ahXIMUkSXX0