To represent the sequence 1, 2, 3, 4, 5, ... recursively, we need to specify the first term and a relationship for subsequent terms.
- The first term \( a_1 \) is 1.
- Each subsequent term can be defined as \( a_n = a_{n-1} + 1 \).
Thus, the correct recursive formula is:
- \( a_1 = 1 \)
- \( a_n = a_{n-1} + 1 \) for \( n > 1 \)
From the options provided, the correct response is:
an=1; an=an−1+1.