Geometric Sequence Lesson

What does r represent?

• Radical

• Common difference

• Common ratio

What does a₁ represent?

• Any term

• First term

• Last term

Find the common ratio for the geometric sequence.

• 10
• 1/2
• 2
• 4

Is the sequence -432, 72, -12, 2,...geometric?

• yes
• no

What are the next 3 terms in the following geometric sequence:

512, 256, 128, ___, ___, ___, ...

• 1024, 2048, 4096

• 32, 8, 2

• 64, 32, 16

• 92, 66, 38

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

Find the first four terms of the sequence given the rule:
a_n = 4(5)^n-1

• 20, 100, 500, 2500
• 5, 20, 80, 320
• 4, 20, 100, 500
• 4, 9, 14, 19

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

Find a₁₂ in the sequence -1, -3, -9, -27, ...

• -177,147
• -19,683
• -59,049
• 118,098