ECZ 2016 · O-Level Paper 2 · Question 5 — Sequences and Series
The first three terms of a geometric progression are x + 1, x - 3 and x - 1.
(a) Simplify x - 1x^2 - 1.[2]
Verified working — step 1
x2 - 1 = …(b(i)) The first three terms of a geometric progression are x + 1, x - 3 and x - 1. Find the value of x.[3]
Verified working — step 1
For a GP the common ratio is the same: x - 3x + 1= x - 1x - 3.(b(ii)) Find the first term.[1]
Verified working — step 1
First term a = x + 1 = 53+ 1 = …(b(iii)) Find the sum to infinity.[3]
Verified working — step 1
r = x - 3x + 1= -4/38/3= …The full step-by-step working and final answer are included with Premium — checked against ECZ marking standards.
Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.
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