2. Aim: What is the arithmetic series ? Do Now: Find the sum of each of the following sequences: a) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 b) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 +... + 98 + 99 + 100 HW: p. 264 # 4,5,7 p.265 # 12,14,16,20,22

3. The sum of an arithmetic sequence is called arithmetic series Although we can find the arithmetic series one after the other, there is a formula to find the series faster.

4. Find the sum of the first 150 terms of the arithmetic sequence 5, 16, 27, 38, 49,... First we need to determine what the last term of the 150 terms (or the 150th term) is. a 1 = 5; d = 16 – 5 = 11. a 150 = a 1 + d(150 – 1), a 150 = 5 + 11(149) = 1644

5. Write the sum of the first 15 terms of the arithmetic series 1 + 4 + 7 + · · · in sigma notation and then find the sum First of all, we need to find the recursive formula a 1 = 1 and d = 3 To find the sum, we need to find a 15

6. We first need to find the 1 st and 35 th term

7. Find the value of the following summation (48 – 15) + 1 = 34 There are 33 terms between 15 th and 47 th term