A geometric sequence is defined by the equation An = (2) 5-2n. What are the first three terms of the sequence and what is the common ratio, r?

Question

Mathematics

Amari Lozano

5 July, 08:36

A geometric sequence is defined by the equation An = (2) 5-2n. What are the first three terms of the sequence and what is the common ratio, r?

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Answers (1)

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Clare Summers · Answer 1

First term = (2) 5^ (-2*1) = 2/25

2nd term = (2) 5^ (-2*2) = 2 / 625

3rd term = 2 (5) ^ (-2*3) = 2 / 15625

If we divide the 3rd term by the 2nd term or the 2nd term by the first we get the common ratio

Common ratio = 1/25 or 0.04 as a decimal fraction.