Final answer:
The sequence 1/2, 1/3, 1/4, 1/5, ... is not arithmetic because the differences between consecutive terms are not constant.
Step-by-step explanation:
To determine whether the sequence 1/2, 1/3, 1/4, 1/5, ... is arithmetic, we need to check if there is a constant difference between consecutive terms.
The difference between the first and second terms is 1/2 - 1/3, which is 1/6 after finding a common denominator.
The difference between the second and third terms is 1/3 - 1/4 = 1/12.
Since the differences are not the same, the sequence is not arithmetic and does not have a common difference.