The Math Meridian
Back to Complex Numbers, Counting and Proof

Proof: deductive proof and induction

Questions at easy, medium and hard levels. Pick a level and get a fresh set every time, with instant feedback.

Useful for: IB Math AA SL & HL

Learn it Deductive proof: start from what is known and use algebra to reach the result for all cases (e.g. let the even number be 2n). Induction: show it's true for n = 1, assume it for n = k, then show it follows for n = k + 1.

Example: Prove the sum of two odd numbers is even.

  1. Let them be 2m + 1 and 2n + 1.
  2. Sum = 2m + 2n + 2 = 2(m + n + 1), which is even.

Loading questions…