Sequences Day 2.notebook
March 24, 2017
Objective
Bell Work
--------------------------Determine if the sequence is arithmetic of geometric. Then write a rule for the sequence and find a10.
Students will learn how to write a
1. ­4, 8, ­16, 32, ­64, ...
geometric sequence when given
2. 17, 14, 11, 8, 5, ...
two terms of the sequence by
rule for an arithmetic or
using the substitution or
elimination method.
Mar 23­3:41 PM
12.2/3 Write a Rule for Sequences
Mar 21­7:45 AM
3/24
Ex. 3: One term of an arithmetic sequence is a19 = 48. The common difference is d = 3.
Ex. 3: One term of a geometric sequence is a4 = 12. The common ratio is r = 2.
a) Write a rule for the nth term.
a) Write a rule for the nth term.
b) Graph the sequence.
b) Graph the sequence.
Mar 21­7:57 AM
Ex. 4: Two terms of an arithmetic sequence are a8 = 21 and a27 = 97. Find a rule for the nth term.
Mar 21­8:00 AM
Mar 21­7:57 AM
Ex. 4: Two terms of a geometric sequence are a3 = ­48 and a6 = 3072. Find a rule for the nth term.
Mar 21­8:00 AM
1
Sequences Day 2.notebook
March 24, 2017
Wrap It Up...
1. What does the graph of an arithmetic and geometric sequence look like?
Assignment
Write a rule for the nth term of the arithmetic or geometric sequence. Arithmetic ~ an = dn + a0
2. Explain why the points on the graphs of sequences aren't connected?
3. Describe the methods used to write a rule for an arithmetic or geometric sequence when only parts of the sequence are provided.
Mar 23­4:05 PM
Geometric ~ an = a1(r)n ­ 1
1. a4 = 96, d = ­14
5. a2 = ­1/4, a4 = ­16
2. a2 = 6, r = 2
6. a4 = 31, a10 = 85
3. a9 = 89, a15 = 137
7. a6 = ­16, d = 9
4. a2 = ­24, a5 = 1536
8. a4 = 500, r = 5
Mar 23­4:08 PM
Homework Help!
Arithmetic ~ an = dn + a0
Geometric ~ an = a1(r)n ­ 1
3. a9 = 89, a15 = 137
5. a2 = ­1/4, a4 = ­16
Mar 23­4:09 PM
2