Paper 1 · Sequences and Series
⏱ Tested in 1 exam question since 2021
Lesson 15 of 15
Proof of Sum to infinity of Geometric sequences
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- Prove S∞ = a/(1−R) by taking the limit of the Sₙ formula as n → ∞
- Apply the convergence fact Rⁿ → 0 when |R| < 1 inside the limit
- Explain why |R| < 1 is essential, contrasting convergent and divergent examples
Most recent exam questions
- 2021 P1 Q7(b)(ii) — 7 marks
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