Given the recursive formula for the arithmetic sequence a1=−5

, an=an−1+4
, find the first three terms of the sequence.(2 points)
a1=
, a2=
, and a3

1 answer

To find the first three terms of the arithmetic sequence given the recursive formula, we start with the initial term \( a_1 = -5 \) and follow the recursive relation \( a_n = a_{n-1} + 4 \).

  1. First Term: \[ a_1 = -5 \]

  2. Second Term: \[ a_2 = a_1 + 4 = -5 + 4 = -1 \]

  3. Third Term: \[ a_3 = a_2 + 4 = -1 + 4 = 3 \]

Thus, the first three terms of the sequence are:

  • \( a_1 = -5 \)
  • \( a_2 = -1 \)
  • \( a_3 = 3 \)