Geometric Sequences, Series and Limiting Sums

What this note covers

1. 1. Geometric Sequences: an = arn−1
2. 2. Proof by Expansion: xn − 1 = (x − 1)(xn−1 + … + x + 1)
3. 3. The Geometric Series Sn
4. 4. Behaviour of an and Sn as n → ∞
5. 5. The Limiting Sum S∞ = a/(1 − r)
6. 6. Geometric Growth and Decay Models
7. 7. Exam Technique and Common Traps

7 sections · 12 key terms & formulas · 6 common mistakes

Common questions