Problem
Write an explicit formula that represents the sequence defined by the following recursive formula: \[ a_{1}=1 \text { and } a_{n}=-2 a_{n-1} \] Answer: \( a_{n}= \) Submit Answer
Solution
Step 1 ：\(a_1 = 1\)
Step 2 ：\(a_2 = -2a_1 = -2\)
Step 3 ：\(a_n = (-2)^{n-1}\)
