Math-a few concepts

Page 1: Axioms

  • Definition of Axioms:

    • Starting points for further mathematical knowledge.

    • Assumed to be self-evident and do not need proof.

    • Provide a foundational base for mathematics, preventing infinite regress in reasoning.

  • Euclid’s 5 Original Axioms of Geometry:

    • Axiom 1: It is possible to draw a straight line between any two points.

    • Axiom 2: A straight line may be extended without limit in either direction.

    • Axiom 3: It is possible to draw a circle given a center and another point.

    • Axiom 4: All right angles are equal to one another.

    • Axiom 5: Through a given point, there is just one straight line parallel to a given line.

Page 2: Deductive Reasoning

  • Definition: Reasoning that progresses from general statements to specific cases.

  • Example Structure:

    • Premise 1: All ostriches are birds.

    • Premise 2: Carlos is an ostrich.

    • Conclusion: Carlos is a bird.

  • In mathematics, premises are axioms, and the conclusion is a theorem.

  • Thus, math is deductive rather than inductive.

Page 3: Theorems & Conjectures

  • Mathematical Theorem:

    • A statement proven based on other accepted statements (theorems or axioms).

  • Conjecture:

    • An unproven hypothesis that appears to work.

    • Coined by philosopher Karl Popper.

    • Does not constitute proof.

  • TOK Question: How is proof defined in mathematics?

Page 4: Defining Mathematical Proof

  • Challenge in Definition: The term "proof" can be difficult to define.

  • Example: Goldbach’s Conjecture:

    • Observational approach: Testing the first 20, 100, or 100,000 even numbers.

    • Inquiry: If it holds for these cases, have you proven it?

    • Deductive Reasoning: Did you utilize this in your approach?

  • Class Connection: Discussion on when observation counts in math and its intellectual satisfaction.

Page 5: Maths and Certainty - The Analytic Argument

  • Analytic View of Mathematics:

    • True by definition, independent of empirical experience.

    • Attributed to philosopher David Hume.

    • Suggests mathematics is a universal truth, with operations revealing inherent truths.

  • Critical Question:

    • Do concepts like even numbers exist independently of human definition?

Page 6: Maths and Certainty - The Empirical Argument

  • Empirical View of Mathematics:

    • From philosopher John Stuart Mill.

    • Certainty arises from repeated empirical observations (correspondence theory).

    • Eg: Confidence in the statement "2+2=4" from numerous validations.

  • Inductive Nature:

    • Although math is inherently deductive, this understanding arises from induction, based on prior observations.

  • Critique:

    • The necessity of proof beyond empirical evidence is evident.

Page 7: Is Maths Discovered or Invented?

  • Scope of Discussion:

    • Relates to the reality of the external world versus the constructs inside the human mind.

  • Tools and Imperfections:

    • Example: Drawing a perfect circle is impossible due to limitations of tools.

    • Measurement Precision: Queries the integrity of measurements and their implications on the existence of mathematical truths.