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 * Aim: How do we use a geometric sequence to solve problems?** //(This formula is not on the Regents Reference Sheet)//

At the end of this lesson, you will be able to...


 * 1) define what is meant by a geometric sequence and its common ratio
 * 2) determine whether a sequence is a geometric, sequence, an arithmetic sequence, or neither
 * 3) determine the common ration, r, for the nth term of a geometric sequence
 * 4) discover the formula for the nth term of a geometric sequence
 * 5) explain how to find a specified term of a geometric sequence
 * 6) solve numeric, algebraic, and verbal problems using the geometric sequence formula

Here are some questions for you to copy into your notebooks and answer as you watch the videos.


 * 1) What is a geometric sequence?
 * 2) How do you determine if a sequence is a geometric sequence?
 * 3) Write the formula for a geometric sequence.

[|Video 1]

[|Video 2]

1. Is the sequence 4, 12, 36, 108, 324,...a geometric sequence? How do you know? (Ans: Yes, there is a common ratio of 3) 2. What is the 10th term of the sequence 4, 12, 36, 108, 324...? (Ans: 78732) 3. Find the four geometric means between 5 and 1215. (Ans: 15, 45, 135, and 405. The common ratio is 3
 * Classwork:**


 * Homework:** Answer numbers 3 - 41 in multiples of 3

[|GeoSquence.JPG]


 * Answers:**

[|A-GeoSequence.JPG]


 * Journal entry:** How can you tell if a sequence is geometric? Compare and contrast an arithmetic sequence with a geometric sequence.