Elementary proofs of some classical stability criteria

Classical stability results and test on the stability of a given polynomial are proved and derived using a simple continuity property. The resulting proofs given of the Hermite-Bieler theorem and the Routh and Jury tests are elementary and full of insight. The proofs allow the instructor to present these fundamental topics of control theory to undergraduates in an elementary, rational, and meaningful way rather than as mere sets of rules and formulae