Question

Given the first term and common ratio: Find the 10th Term. The first term is equal to 1 and the common ratio is

equal to -2.

Answer 1

-512

Explanation:

The appropriate general formula for a geometric series is a(n) = a(1)*r^(n - 1).

In this problem the first term, a(1) = 1, and the common ratio is r = -2. The pertinent geometric series is thus:

a(n) = (-2)^(n - 1), and the 10th term is a(10) + (-2)^(10 - 1) = -512 = a(10)