Question

what is the common ratio for this sequence? 1,-1 1. 1. 1 - , -, – -, -,... 3 9 27 81

Answer 1

The common ratio of a sequence can be determined by dividing each number in the sequence from the number preceding it.

We can use the first term and the second term to find the common ratio.

First-term = 1

Second term = -1/3

Therefore the common ratio is;

`\begin{gathered} \text{Common ratio =}\frac{\sec ond\text{ term}}{\text{first term}}=(-(1)/(3))/(1) \\ =-(1)/(3) \end{gathered}`

The answer is -1/3