Geometric Find First Term

A geometric sequence has a common ration(r) of 2 and the 13th term (a₁₃) is 36,864. What is the first term of the sequence (a₁)?

• 3

• 9

• 18

• 6

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 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

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

• -177,147

• -19,683

• -59,049

• 118,098

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

What does a₁ represent?

• Any term

• First term

• Last term

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

• yes

• no

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

• arithmetic

• geometric

• neither

This image shows how a certain bacteria grows in a petri dish. What is the common ratio of this sequence?

• 4

• 3

• 2

• 6

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