Talk:Associative Composition Algebra

Acknowledgment
The wikibook Associative Composition Algebra would not have been possible without the coaching of some Encyclopedia editors. It did not happen overnight, and there were twists and turns. This review is but a synopsis of events that can be confirmed by clicking on History of any article. In August, October, and November 2004 I posted articles on Split-complex numbers, Tessarines and Biquaternions. An article on Hyperbolic angle was also posted that November. And in December the first Inversive Ring Geometry was posted. February 2005 saw Coquaternion posted, citing James Cockle (1851).

In June 2007 Coquaternion was moved to Split quaternion, and that began the shift from Cockle's terminology to that used with composition algebra. In November 2010 Tessarine was moved to Bicomplex number, completing the shift. And in February 2013, after encouragement from another editor, I moved Inversive ring geometry to Projective line over a ring, aligning with general usage. Thus the wikibook provides a gloss on articles in the Encyclopedia that developed over a decade of collaboration.

Exercises
Learning mathematics involves doing mathematical exercises. Today some were included in the Quaternions chapter. Each chapter should have some, as a college lecturer gives out exercises for the class to work on for the next meeting. Exercises develop insight and technique, and can be used to attain mastery of the subject. Suggestions are solicited. Rgdboer (discuss • contribs) 00:14, 30 April 2017 (UTC)

Some resources for developing suitable exercises
The following sources, nominally about C, may contain statements using * that generalize to AC algebras:
 * Constantin Caratheodory (1932) Conformal Representation, Cambridge Tracts in Mathematics and Mathematical Physics #28, Cambridge University Press.
 * Andrew Forsyth (1910) "Plane curves invariant under homographic transformation", Quarterly Journal of Pure and Applied Mathematics 41: 113 to 127.
 * Andrew Forsyth (1911) "Equations of plane geometry expressed by means of complex variables", Quarterly Journal of Pure and Applied Mathematics 42: 1 to 40.
 * Frank Morley & F.V. Morley (1933) Inversive Geometry, (reprint 1954 by Chelsea Publishing)
 * Hans Schwerdtfeger (1962) Geometry of Complex Numbers, University of Toronto Press.
 * Isaak Yaglom (1968) Complex Numbers in Geometry, Eric Primrose translator, Academic Press.

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