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 OCR A Level Maths 1.1 Proof, covering 1.1.1 Structure of mathematical proof, 1.1.2 Logical connectives, 1.1.3 Disproof by counter example, 1.1.4 Proof by contradiction (A-level only), and 1.1 Proof. Each one has a worked solution and a mark scheme showing where the marks go.