Easy -2.5 This is a trivial recall question requiring only recognition that (-1)^n alternates between -1 and 1, giving period 2. It's a single-mark circle-the-answer question with no calculation or reasoning required, making it significantly easier than typical A-level questions.
2 A periodic sequence is defined by
$$U _ { n } = ( - 1 ) ^ { n }$$
State the period of the sequence.\\
Circle your answer.
\hfill \mbox{\textit{AQA Paper 1 2022 Q2 [1]}}