Question

A geometric sequence has a common ration(s) of 3 and the 8th term (a8) is 13,122. What

is the first term of the sequence (a1)?

Answer 1

First term a = 6

Explanation:

a (first term) = ?

r (common ratio) = 3

T₈ (8th term) = 13122

The nth term of a geometric progression gp is

Tn = arⁿ⁻¹

T₈ = ar⁸⁻¹

T₈ = ar⁷

13122 = a * 3⁷

13122 = a * 2187

a = 13122 / 2187

a = 6.

The first term a = 6