To identify the explicit formula for the sequence \(12, 6, 0, -6, \ldots\), let's first observe the pattern of the sequence.
- The first term \(a_1 = 12\)
- The second term \(a_2 = 6\)
- The third term \(a_3 = 0\)
- The fourth term \(a_4 = -6\)
From this, we can see that each term decreases by \(6\):
- From \(12\) to \(6\) is \(-6\)
- From \(6\) to \(0\) is \(-6\)
- From \(0\) to \(-6\) is \(-6\)
Thus, the common difference \(d\) is \(-6\). Therefore, this sequence is an arithmetic sequence. The formula for the \(n\)th term of an arithmetic sequence can be expressed as:
\[ A_n = A_1 + (n - 1) \cdot d \]
where:
- \(A_1 = 12\) (the first term)
- \(d = -6\) (the common difference)
Substituting these values into the formula, we get:
\[ A_n = 12 + (n - 1)(-6) \]
Thus, the correct explicit formula that represents the sequence is:
\[ A_n = 12 + (n - 1)(-6) \]
So, from the options provided, the correct response is:
An=12+(n−1)(−6)