1. 12-1 Arithmetic Sequences and Series

2. Sequence- A function whose domain is a set of natural numbers Arithmetic sequences: a sequences in which the terms vary by a common difference Notation: a 1, a 1 + d, a 1 + 2d, a 1 +3d….

3. Practice: 1) Find the next four terms in the sequences: -5, -2, 1,…

4. Recursive formula: a formula that requires computations of the previous terms, to find the current term. If you don’t want to find all the previous numbers, you can use the formula A n = a 1 + (n-1)d

5. Practice: 2) Find the 47 th term in the sequence -4, -1, 2, 5…. 3) Find the first term in the arithmetic sequence for which a 19 = 42 and d= -2/3

6. 4) Write an arithmetic sequence that has five terms between 4.9 and 2.5

8. 5) Find the sum of the first 60 terms in the series 9 + 14 + 19+….+ 304