Question

What are the explicit equation and domain for an arithmetic sequence with a first term of 5 and a second term of 2? (5 points)

Answer 1

The third choice is appropriate.
  an = 5 - 3(n - 1); all integers n ≥ 1

_____
This equation follows the form for the general term of an arithmetic sequence.
  an = a1 + d(n - 1)
where a1 is the first term (corresponding to n=1), and d is the common difference. From the problem statement, a1 = 5 and d = 2 - 5 = -3.