Question

Is the following sequence

arithmetic, geometric, or
neither? Give the common
difference or ratio.
{-3, 6,-9, 12, ...}

Answer 1

Neither

Explanation:

If the sequence is arithmetic, there will be a common difference.

6 − (-3) = 9

-9 − 6 = -15

12 − (-9) = 21

The sequence is not arithmetic.

If the sequence is geometric, there will be a common ratio.

6 / -3 = -2

-9 / 6 = -3/2

12 / -9 = -4/3

The sequence is not geometric.