Sequences and Sigma Notation

Identify the common difference.
-21, -18, -15, -12, ...

• 4

• 3

• -4

• -3

Find the next three terms in the arithmetic sequence: 9, 19, 29, 39, ...

• 45, 54, 63

• 49, 59, 69

• 39, 49, 59

• 59, 69, 79

Write the recursive formula for 4, 8, 12...

• a_n=a_n-1-7

• a_n=a_n-1-4

• a_n=a_n-1+3

• a_n=a_n-1+4

What is the distance from one number to the next in a sequence of numbers that is represented by a (d) in an arithmetic sequence?

• Common denominator

• Common opposites

• Common domain

• Common difference

Given the sequence:
125, 25, 5, ....
Write the explicit rule:

•  t(n) = (125)(5)⁽ⁿ⁾

•  t(n) = 625(1/5)⁽ⁿ⁾

•  t(n) = 625(5)⁽ⁿ⁾

•  t(n) = 125 + 5n

Is the sequence geometric or arithmetic?
6, 18, 54...

• Arithmetic

• Geometric

• Neither

Given the sequence:
 25, 21, 17, 13,...
Write the explicit equation that models the sequence.  (Hint:  Simplify your equation.)

• a_n = 4n + 29

• a_n = -4n + 25

• a_n = -4n + 29

• a_n = 4n + 25

Create the explicit formula for the sequence:
2, 8, 14, ...
(Hint:  Write your formula and then simplify it.)

• a_n=2+6n

• a_n=-6+6n

• a_n=6n-4

• a_n=4-6n

Find the next three terms: 4, 12, 36, 108, ...

• 324, 972, 2916

• 972, 2916, 8748

• 405, 1215, 3645

Find the general rule for: 64, -32, 16, -8, …  

• 64(1/2)^n-1

• (-32)^n-1

• 64(-1/2)^n-1

• (32)^n-1