1. **Problem Statement:** Given the arithmetic sequence $-15, -7, 1, 9, \ldots$, write the recursive formula, explicit formula, and find the 52nd term using the explicit formula.
2. **Identify the first term and common difference:**
- The first term $a_1 = -15$.
- The common difference $d$ is found by subtracting the first term from the second term:
$$d = -7 - (-15) = -7 + 15 = 8$$
3. **Write the recursive formula:**
The recursive formula for an arithmetic sequence is:
$$a_n = a_{n-1} + d$$
with the initial term:
$$a_1 = -15$$
So,
$$a_n = a_{n-1} + 8, \quad a_1 = -15$$
4. **Write the explicit formula:**
The explicit formula for the $n$th term of an arithmetic sequence is:
$$a_n = a_1 + (n-1)d$$
Substitute $a_1 = -15$ and $d = 8$:
$$a_n = -15 + (n-1) \times 8$$
Simplify:
$$a_n = -15 + 8n - 8 = 8n - 23$$
5. **Find the 52nd term using the explicit formula:**
$$a_{52} = 8 \times 52 - 23$$
Calculate:
$$a_{52} = 416 - 23 = 393$$
**Final answers:**
- Recursive formula: $a_n = a_{n-1} + 8$, $a_1 = -15$
- Explicit formula: $a_n = 8n - 23$
- 52nd term: $393$
Arithmetic Sequence 59Ac6F
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