To determine whether the sequence 9, 4, −1, −6, ... is arithmetic, geometric, or some other type, we can analyze the differences and ratios between consecutive terms.
- Arithmetic Sequence: In an arithmetic sequence, the difference between consecutive terms is constant.
- Difference between terms:
- \( 4 - 9 = -5 \)
- \( -1 - 4 = -5 \)
- \( -6 - (-1) = -5 \)
- The difference is the same (-5) for all pairs of consecutive terms.
- Difference between terms:
Since the difference is constant, we can conclude that this sequence is an arithmetic sequence.
Thus, the answer is: arithmetic sequence