Geometric Algebra
Geometric algebra, the solution of algebraic
problems by geometric constructions, is
another thread. Here are the principal milestones:
- 2000 BC Babylonian scribes describe solving quadratic equations
- 300 BC Euclid's Elements, esp:
- Book I Prop. 44;
- Book II Props. 4, 5, 6, 11;
- Book VI Props. 28, 29
- 800 AD Al-Khwarizmi, explicit solution of quadratic Babylonian style
- 1220 AD Leonardo of Pisa, Practica Geometriae follows
Al-Khwarizmi
Cf. (Katz, 1993). pp. 65, 231-233, 270, 273, 282.
Ralph H. Abraham, 13 May 1996.