Methods of Proof (Contradiction & Counterexamples)

Methods of proof develops the Proof topic in NSW Year 12 Mathematics Extension 2 (NESA outcome ME2-12-01). This subtopic uses proof by contradiction to establish the truth of mathematical statements and uses examples and counterexamples to test whether a statement is true or false.

Students and teachers will cover how to structure a proof by contradiction, disprove a claim with a single counterexample, and prove results involving integers — such as properties of odd and even numbers and divisibility — which are core reasoning techniques in the HSC Extension 2 course.