Geometric Sequence

Definition of Geometric Sequence

  • Geometric sequence is a sequence in which each term after the first term a is obtained by multiplying the previous term by a constant r, called the common ratio. It is obvious that and or 1.

1, 2, 4, 8, 16, 32, . . . is a geometric sequence.

Each term of this geometric sequence is multiplied by the common ratio 2.

More about Geometric Sequence

  • Geometric series is the indicated sum of the terms of a geometric sequence.
For the geometric sequence 1, 2, 4, 8, 16, 32, 1 + 2 + 4 + 8 + 16 + 32 is the corresponding geometric series.
 

Solved Example on Geometric Sequence

Find the 5th term of the geometric sequence  

Choices:

A. 9

B. 3

C. 81

D. 27           

Correct Answer: D

Solution:

Step 1: In a geometric sequence, the nth term is given by .                               

Step 2: To find the fifth term, substitute n = 5 in the formula.

Step 3: The 5th term is .        [Substitute and simplify.]

Related Terms for Geometric Sequence

  • Sequence
  • Term
  • Common Ratio
  • Geometric Series
  • Constant

Additional Links for Geometric Sequence