Find a Formula for the Nth Term of the Sequence $9 , - 9,9 , - 9,9$

question 146

Multiple Choice

Find a formula for the nth term of the sequence.
- $9 , - 9,9 , - 9,9$ (9's with alternating signs)

• A) \(a _ { n } = 9 ( - 1 ) ^ { 2 n + 1 }\)
• B) \(a _ { n } = 9 ( - 1 ) ^ { n + 1 }\)
• C) \(a _ { n } = 9 ( - 1 ) ^ { 2 n - 1 }\)
• D) \(a _ { n } = 9 ( - 1 ) ^ { n }\)

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