Question

The formula for any geometric sequence is an = a1 · rn - 1 , where a n represents the value of the n th term, a1 represents the value of the first term, r represents the common ratio, and n represents the term number. What is the formula for the sequence -3, -6, -12, -24, ...?

Answer 1

an = -3·2^(n-1)

Explanation:

The first term is a1 = -3.

The common ratio is r = -6/-3 = 2.

The given formula tells you the formula for this sequence is ...

an = -3·2^(n-1)