Proof is central to mathematics inquiry. It is at the heart of what we mean when we claim to know that a mathematical result is true. Proving theorems is the exciting, frustrating, and unavoidable challenge faced by all mathematics researchers. Proofs are also a means of gaining insight into a mathematical question.
Consult the discussions and exercises in the proof section of the teacher handbook.
For specific proof techniques, see:
See also Moment of Truth and the essays in The Mathematical Experience by Philip Davis and Reuben Hersh published by the Houghton Miffllin Company (see sample essays Proof and The Prime Number Theorem).
Translations of mathematical formulas for web display were created by tex4ht.