OCR FP3 2013 January — Question 2

Exam BoardOCR
ModuleFP3 (Further Pure Mathematics 3)
Year2013
SessionJanuary
TopicGroups

2 The elements of a group \(G\) are the complex numbers \(a + b \mathrm { i }\) where \(a , b \in \{ 0,1,2,3,4 \}\). These elements are combined under the operation of addition modulo 5 .
  1. State the identity element and the order of \(G\).
  2. Write down the inverse of \(2 + 4 \mathrm { i }\).
  3. Show that every non-zero element of \(G\) has order 5 .