Title

Idempotents à la mod

Document Type

Article

Publication Date

11-2012

Abstract

An idempotent satisfies the equation x2 = x. In ordinary arithmetic, this is so easy to solve it’s boring. We delight the mathematical palette here, topping idempotents off with modular arithmetic and a series of exercises determining for which n there are more than two idempotents (mod n) and exactly how many there are.