OCR FP3 2010 June — Question 2

Exam BoardOCR
ModuleFP3 (Further Pure Mathematics 3)
Year2010
SessionJune
TopicGroups

2 A multiplicative group with identity \(e\) contains distinct elements \(a\) and \(r\), with the properties \(r ^ { 6 } = e\) and \(a r = r ^ { 5 } a\).
  1. Prove that r ar \(= a\).
  2. Prove, by induction or otherwise, that \(r ^ { n } a r ^ { n } = a\) for all positive integers \(n\).