JEE Maths
JEEMathsSequences & SeriesClass 11

What does “Infinite geometric series” actually mean in Sequences & Series, and why does it matter for JEE?

an infinite GP has a finite sum a/(1−r) only when |r| < 1.

In simple words: an infinite GP has a finite sum a/(1−r) only when |r| < 1. Getting Infinite geometric series clear matters because JEE questions on Sequences & Series usually test this idea directly, not just a formula you memorised.

Key point

Infinite geometric series

Common mistake

applying the sum formula when |r| ≥ 1.

Memory tip

if the terms don't shrink (|r|≥1), the series diverges — no finite sum.

Tap to watch or see it right here — the app stays open (it only opens a quick search if nothing embeddable is found).

More on Sequences & Series