Class Opener:  For each sequence find: 𝑡 1 , 𝑡 7 , 𝑎𝑛𝑑 𝑑 1.

-1, 3,7 2.

5,2,-1 3.

22.3,17.6,12.9

Explicit Formula:

𝑎

𝑛

= 𝑎

1

+ 𝑛 − 1 𝑑

You can use the explicate formula to find the value of the nth term of an arithmetic sequence when the previous term is unknown.

Using the Explicit Formula:  Use the explicit formula to find the 25 th sequence: term in the

5,11,17,23,29

Find the 32 nd term in each: 1.

34,37,40,43…… 2.

23, 30, 37, 44…..

3.

9, 4, -1, -6, -11….

4.

0.1, 0.5, 0.9, 1.3

Writing the Recursive Formula Write the recursive formula for each sequence: 1.

2,4,6,8,10… 2.

0,6,12,18,24… 3.

-2, 5, 12, 19, 26, 32…

Using the Explicit Formula:  Suppose you participate in a bike-a-thon for charity. The charity starts with $1100 dollars in donations. Each participant must raise at least $35 dollars in pledges. What is the minimum amount of money raised if there are 75 participants?

Using the Explicit Formula:  Suppose you have already saved $75 dollars for an Ipad 2. You plan to save at least $12 dollars a week. How much money will you have after 26 weeks?

Movie Time: Pair up with the person beside you: Use arithmetic sequences and the explicit formula to complete the following activity.