Question

Find the explicit rule for the geometric sequence of 3, -6, 12, -24

Answer 1

The n-th term of this sequence is 3(-2)^(n-1)

Explanation:

Term 1 = 3 = 3 X 1 =. 3(-2)^0

Term 2 = -6 = 3 X (-2) = 3(-2)^1

Term 3 = 12 = 3 X (-2) X (-2) = 3(-2)^2

…

The first term is 3, and every subsequent term is the previous term multiplied by -2.