A simple demonstration of zero factorial equals one

Abstract

When asked, a number of students answer zero factorial to be zero as a continuation to the answer of one factorial to be one. Any instructor would then seek a justification of zero factorial to be one from computing _nC_n via the well- known combination formula. This article conveys a simple presentation of zero factorial to be one based on lower and upper bounds of n factorial. We have not seen this explanation covered in any algebra textbook.

Keywords:

• factorial
• bound
• limit

Disclosure statement

No potential conflict of interest was reported by the authors.