Question

Given the first five terms of the sequence 3, 7, 11, 15, 19 . . .
, determine which option is the correct subscript notation for the explicit formula.

Option #1: an=3+4n


Option #2: an=4+3n


Option #3: an=−1+4n


(1 point)
Option #

Answer 1

Option #3.

Reason: This is an arithmetic sequence with a1 = 3 and common difference d = 4.
a_n = a1 + (n−1)d = 3 + (n−1)·4 = −1 + 4n, which gives 3, 7, 11, 15, 19…