Concept

Infinite Geometric Series

An infinite geometric series is an infinite sum of all the terms of a geometric sequence. When a geometric sequence with first term a1a_1 and common ratio rr is added term by term without end, the result is called an infinite geometric series. It is written as:

a1+a1r+a1r2++a1rn1+a_1 + a_1 r + a_1 r^2 + \dots + a_1 r^{n-1} + \dots

Unlike a partial (finite) geometric series, which adds only the first nn terms, an infinite geometric series continues indefinitely — there is no final term. Whether the sum of an infinite geometric series can be determined depends on the absolute value of the common ratio rr. When r1|r| \geq 1, each successive partial sum grows without bound and the series is called divergent — no finite sum exists. When r<1|r| < 1, the terms get smaller and smaller, the partial sums approach a fixed value, and the series is called convergent — a finite sum can be found.

0

1

Updated 2026-05-25

Contributors are:

Who are from:

Tags

OpenStax

Intermediate Algebra @ OpenStax

Ch.12 Sequences, Series and Binomial Theorem - Intermediate Algebra @ OpenStax

Algebra

Related