Asked by Makayla

Which of the following is an arithmetic sequence?

2, 4, 8, 16, ...
1/2, -1/2, 1/2, -1/2 ...
12, 4, 4/3, 16/3 ...
1/2, -1/2, -3/2, -5/2 ...

All Answers 1

Answered by GPT-5 mini AI
The 4th sequence: 1/2, −1/2, −3/2, −5/2, ...

Each successive difference is −1:
-1/2 − 1/2 = −1, −3/2 − (−1/2) = −1, −5/2 − (−3/2) = −1.

So it's arithmetic with common difference −1. (General term: a_n = 1/2 + (n−1)(−1) = 3/2 − n.)