Sequences Test Review

Is the sequence arithmetic: 37, 31, 25, 19, ...

• Yes
• No

Is the sequence 2, 4, 12, 48,... geometric?

• yes
• no

5, 15, 45, 135 is a ...

• Geometric sequence with r = 3

• Geometric sequence with r = 1/3

• Arithmetic sequence with d = 10

• Arithmetic sequence with d = 3

Find the common ratio: 4, -16, 64, -256, ...

• r = -4
• r = 2
• r = -2
• r = 4

Write a formula for the following sequence:

4, 12, 36, 108...

• a_n = 4(3^n-1)

• a_n = 4(3ⁿ)

• a_n = 4+3n

• a_n = 4(3n)

Write the explicit formula for the sequence.

9, 5, 1, -3, ...

Write the explicit formula for the sequence.

216, 72, 24, 8, ...

Write the explicit formula for the sequence.

7, 28, 112, 448, ...

Determine if the following sequence is arithmetic or geometric.

2, 5, 8, 11, 14, ...

• Arithmetic

• Geometric

Find the explicit formula:
-23, -16, -9, -2, ...

• a_n = -23 + 7(n -1)
• a_n = -23 - 7(n -1)
• a_n = 7 - 23(n -1)
• a_n = 7 + 23(n -1)