Al-Khwarizmi
Mathematician · c. 780-850 · Mathematics, stage 3: Meet the mathematicians
Wrote the book that gave algebra its name and supplied general methods where there had been individual tricks.
Overview
Al-Khwarizmi worked in Baghdad under the Abbasid caliphate. His book on al-jabr and al-muqabala, written around 820, classifies quadratic equations into standard types and gives a procedure for each, justified geometrically by completing a square; the two Arabic terms name the operations of restoring a subtracted quantity to the other side and balancing like terms, and the first of them became the word algebra. Everything is written in words, with no symbols and no negative numbers, which makes the text harder to read than its mathematics requires. A separate work explained the Hindu-Arabic decimal system, and its Latin translation carried both the numerals and, from the Latin form of his name, the word algorithm into Europe. Read a translated extract next to MacTutor's survey of the period.
Where to start reading
The Compendious Book on Calculation by Completion and Balancing (al-jabr wa'l-muqabala) c. 820
The founding text of algebra as a subject: standard forms of linear and quadratic equations, a general procedure for each, and geometric arguments that the procedures work.
On the Calculation with Hindu Numerals c. 825
An account of the decimal place-value system, surviving mainly in Latin translation, which is how those numerals reached Europe.
Part of
Sources
- Al-Khwarizmi MacTutor History of Mathematics
- Al-Khwarizmi Wikipedia
- Arabic mathematics MacTutor History of Mathematics
