Geometric Sequences

Find the common ratio for the geometric sequence.

• 10
• 1/2
• 2
• 4

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

• yes
• no

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

• r = -4
• r = 2
• r = -2
• r = 4

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

• arithmetic
• geometric
• neither

What is the 14th term of the geometric sequence?

• 14,348,907
• 4,782,969
• 1,594,323
• 45

Given the sequence:

125, 25, 5, ....

Write the rule a_n using the geometric sequence formula:

• a_n = (125)(1/5)^(n-1)

• a_n = 625(1/5)^(n-1)

• a_n = 625(5)^(n-1)

• a_n = 125 + 5n

The rule for finding a_n of a geometric sequence is

a_n = 10(2)^n-1 _{What is the common ratio(r) of the sequence?}

• ²

• ¹⁰

• ²⁰

• 2ⁿ

What is the 9^th term in a geometric sequence with a common ratio of 2 and a first term of 3?

• 384

• 768

• 1,536

• 27

Daisy received $2 on her first birthday. Each year, the amount of money she received tripled. How much money will she receive on her 5^th birthday?

• $10

• $300

• $162

• $416

Write the explicit formula for the geometric sequence.

• a_n = 4(3)^n-1
• a_n = 3(4)^n-1
• a_n = -4(3)^n-1
• a_n = 3(-4)^n-1