Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-28T08:28:11.668Z Has data issue: false hasContentIssue false

A serendipitous path to a famous inequality

Published online by Cambridge University Press:  01 August 2016

Robert M. Young*
Affiliation:
Department of Mathematics, Oberlin College, Oberlin, OH 44074USA, e-mail: [email protected]

Extract

The mysterious path of discovery – the tireless experimentation in search of patterns, the veiled connections that suddenly unfold, serendipity – all these elements combine to make mathematics so magical. The purpose of this note is to show how a routine algebraic identity, the binomial expansion of (x - 1)2, can be used to give a new proof of the fundamental inequality between the arithmetic and geometric means. The proof will provide further evidence that a great deal of useful mathematics can be derived from the obvious assertion that the square of a real number is never negative.

Type
Articles
Copyright
Copyright © The Mathematical Association 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Hardy, G.H., A mathematician’s apology, Cambridge University Press, (1979).Google Scholar
2. Hardy, G.H., Prolegomena to a chapter on inequalities, J. London Math. Soc. 4 (1929) pp. 6178.Google Scholar
3. Euclid, , The thirteen books of Euclid’s elements (translated by Sir Thomas Heath), Cambridge University Press (1908).Google Scholar
4. Maclaurin, C., A second letter to Martin Folkes, Esq; concerning the roots of equations, with the demonstration of other rules in algebra, Phil. Transactions, 36 (1729), pp. 5996.Google Scholar
5. Cauchy, A.L., Cours d’analyse de l’ⴚÉole Royale Polytechnique. Ire partie. Analyse algébrique, Imprimerie royale, Paris (1821).Google Scholar
6. Niven, I.M., Maxima and minima without calculus, Mathematical Association of America, Washington, D.C. (1981).Google Scholar
7. Pólya, G., Induction and analogy in mathematics, Volume 1 of Mathematics and plausible reasoning, Princeton University Press (1954).Google Scholar
8. Young, R.M., Excursions in calculus: an interplay of the continuous and the discrete, Mathematical Association of America, Washington, D.C. (1992).Google Scholar