Geometric Progression

What is a geometric progression?

A geometric progression is one in which there is a common ratio between each successive term in the progression.

Example of a geometric progression

2, 4, 8, 16, 32, 64, ..

This is a geometric progression because each successive term is equal to the previous term x 2. Another geometric progression is shown below.

2, 10, 50, 250, 1250, ...

This geometric progression has a common ratio of 5.

General form of geometric progression

Where

• a = the first term of the geometric progression
• r = constant ratio of each term of the geometric progression
• n = number of terms in the geometric progression

Note that the nth term of the geometric progression or geometric series is ar ^n-1.