P2.1.3 - Disproof by counter example

Disproof by counter example.; Disproof by counter example – show that the statement “n2 − n + 1 is a prime number for all values of n” is untrue.

Use disproof by counter example to connect the rule to the data and decision in the question.

This matters because disproof by counter example determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply disproof by counter example to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: Disproof by counter example is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.