Maths with Lemon

Proofs

"Pure mathematics is, in its way, the poetry of logical ideas."

Albert Einstein

Proof by induction

Prior Knowledge

Key points

  • 1. Watch the video:

Proof by contradiction

Prior Knowledge

  • To manipulate algebraic expressions with exponents

Key Points

  • 1. Watch the video:

Extra

Material and references:

  • Hodder Book HL(ISBN: 9781510462366) :
    5A, 5B, 5C

Key Points

  • 1. You should be able to use the principle of mathematical induction to prove statements about patterns involving integers. If you can show that the statement is true for \( n = 1 \), and that when the statement is true for \( n = k \) it is also true for \( n = k + 1 \), then the statement is true for all positive integers \( n \). The proof can be adapted for a starting value other than \( n = 1 \).

  • 2. You should be able to use proof by contradiction: assume that the statement you are trying to prove is false and show that this leads to an impossible or contradictory conclusion.

  • 3. You should be able to use counterexamples to disprove a statement. One counterexample is sufficient to prove that a statement is false.

IB Past Paper Problems

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