Use proof by contradiction to show that for all real values of xxx,
(x−6)2≥2x−46 (x - 6)^2 \geq 2x - 46 (x−6)2≥2x−46Show that the following statement is untrue:
"2n+2n−12^n + 2n - 12n+2n−1 is a prime number for all values of n∈Z+n \in \mathbb{Z}^{+}n∈Z+."
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.