Identifying and writing sequences

What are arithmetic sequences?

• Arithmetic sequences are sequences where you add or subtract the same number to get the next term.

• Arithmetic Sequences are sequences where you are multiplying or dividing by the same number to get the next term.

What kind of sequence is illustrated below?
 400, 200, 100, 50, 25, ...

• Arithmetic
• Geometric
• Neither

Which of the following is explicit?

• $f_n=4n+5$

•  $f_n=5f_{n-1}$  

Determine whether the sequence is arithmetic, geometric, or neither.

• arithmetic
• geometric
• neither

What number follows 20 in this arithmetic sequence?

8,11, 14, 17, 20

• 5

• 23

• 26

• 29

In a geometric sequence, if a1 = 3 and r = 2, what is the value of a6?

• 96

• 48

• 192

• 64

Find the 16th term of the sequence 1, 5, 9, 13, ...

• 60

• 61

• 64

• 65

An arithmetic sequence is given below.

2, 9, 16, 23, ...

Which is the explicit formula for the n^th term a_n?

(Look at the choices carefully! You may have to simplify your equation to get the correct choice!)

• a_n = -7n+9

• a_n = 7n-5

• a_n = 7n-9

• a_n = -7n+5

Which number is missing in this pattern? 
62, 68, 76, 82, 90, 96 ___, 110

• 102
• 106
• 104
• I don't know

Which of the following is NOT a geometric sequence?

• 6,18,54,162

• 14,28,42,56

• 2,18,162,1458

• 8,24,72,216