A cybersecurity algorithm generates security keys using integers of the form n=6k−1n = 6k - 1n=6k−1, where k∈Zk \in \mathbb{Z}k∈Z.
Prove by contradiction that there is no greatest integer of this form.
107 exam-style questions on AQA A Level Maths 1.4.1 Structure and methods of proof. Each one has a worked solution and a mark scheme showing where the marks go.