Math 3000 - Lecture 4
What is a proof?
Proofing as a social process, a communication art.
Rigor in proofs.
Methods of Proof
- If n is an odd integer, then n2 is odd.
- Do converse of above.
If A and B are integers and B 0. Show that if A divides B then |A| |B|.
- The sqrt(2) is irrational.
- The importance of definitions.
- Working backwards.
- Iff proofs.
- Uniqueness proofs.
- Proof by cases.
Some basic number theory: Divisibility, Congruence.