1. Bellwork Find the next two terms of each sequence.
1) -1, -5, -25, _____, ____
2) -8, -2, 4, 10, _____, ____
3) Find the first five terms of the sequence an = 7n + 2

2. Section 11-2 Arithmetic Sequences and Series
Algebra 2
Spring 2012

3. Arithmetic Sequence
In arithmetic sequences, there is a common difference d.
This is the number that you add every time to get the next term.
Is it arithmetic? What is the common difference?
A) 2, -3, -8, -13, …. C)
B) D)

4. Example 1
Write the first 5 terms if and d = -7.

5. Example 2 Rule for Arithmetic Sequences: common difference
first term
common difference
Write the rule for the given information.
A) a1 = 2, d = 3 B)

6. Example 3 Find the indicated term of each arithmetic sequence.
a1 = -4, d = 6, n = 9
a20 for a1 = 15, d = -8

7. Example 4
Write the equation for the nth term of each arithmetic sequence.
31, 17, 3, ….
a7 = 21, d = 5
a6 =12, d = 8

8. Example 5 Find the arithmetic means in each sequence.
6, ____, ____, ____, 42
24, _____, _____, _____, _____, -1

9. Example 6
Use the given information to write an equation that represents the nth term in each arithmetic sequence.
The 19th term of the sequence is The 61st term is 509.

10. EOI Question
DOK 1

11. Section 11.2 Homework pt. 1
Pg – 38 even, 63-66

12. Bellwork Write the series with summation notation.1)
Find the sum of the series 2)

13. Section 11.2 Part 2
Finding the Sum of the Arithmetic Sequence (finite)
Find the sum of the first 50 even natural numbers.
Find the sum if a1 = 3, d = 6, n = 25.

14. Example 1
Find the sum of the arithmetic sequence if n = 16, d = 8, an = 240.
Find the sum of … + 180

15. Example 2
Find the sum of the arithmetic sequence when written in summation notation.

16. Section 11.2 Part 2 Homework
Pg , 57, 60