1. Recursive & Explicit Formulas
January 5 – 7, 2010

2. Closed/Explicit Formula
January 6, 2010
Closed/Explicit Formula

3. Warm Up (1/6)
You can burn 5 calories a minute from walking. Which set could represent the range of calories burned when walking between 1 and 5 minutes?
a. {1,2,3,4,5} c. {5}
b. {5,10,15,20,25} d. {1,5}
Which sequence is not a linear function?
a. 1,2,3… c. 2,5,8…
b. 1,4,9 d. -12,-8,-4…
Given the first term in the sequence below, use the recursive formula given to find the next four terms of the sequence.
a. 15,12,9,6 c. -3,6,12,18
b. 18,15,12,9 d. 18,12,6,-3

4. Explicit Formula for the nth term of a sequence
nth term 1st term # of common
the term difference
trying to
find
Find the indicated term.

5. What is the 23rd term of the following sequence?
5, 12, 19, 26, …
a1 = 5; d = 7

6. You Try! Find the 9th term in the following sequence: 9, 2, -5, -12,…
a1 = 9; d = -7

7. Practice
13, 25, 37, 49,… find the 25th term
a1 = 13; d = 12

8. Write the equation for the nth term
17, 28, 39, 50, …
a1 = 17; d = 11
7, 4, 1, -2, …
a1 = 7; d = -3

9. Sequence 1: -4, 1, 6, 11, … Find common difference (d)
Write the sequence in explicit /closed form: tn = t1 + (n-1)d
tn = (n-1)(5)
Find the 10th term ---
Find the 25th term ---

10. Sequence 2: 8, 5, 2, -1, … Find common difference (d)
Write the sequence in explicit/closed form:
tn = t1 + (n-1)d
tn = 8 + (n-1)(-3)
Find the 10th term ---
Find the 25th term ---

11. Sequence 3: -2, -4, -6, -8, … Find common difference (d)
Write the sequence in explicit/closed form: tn = t1 + (n-1)d
tn = (n-1)(-2)
Find the 10th term ---
Find the 25th term ---

12. Sequence 4: 4, 7, 10, 13, … Find common difference (d)
Write the sequence in explicit/closed form: tn = t1 + (n-1)d
tn = 4 + (n-1)(13)
Find the 10th term ---
Find the 25th term ---

13. Homework
Textbook p. 145; and 45 ALL