Samaw'al al-Maghribi

Origins and early life

Samaw'al al-Maghribi was born in Baghdad about 1130 into a Jewish family: his father, Yehuda ibn Abbas, was a rabbi and Hebrew poet from Fez in Morocco and a friend of Judah Halevi, and his mother, Anna Isaac Levi, came from Basra.

Work and career

This fiche states plainly that he did not remain Jewish: he converted to Islam at Maragha on 8 November 1163, after delaying for years out of regard for his father, and he afterwards wrote a polemical tract against Judaism, Ifham al-Yahud, whose arguments were used against Jews for centuries; the site records him for what he did in mathematics while stating that fact openly. He was largely self-taught in mathematics from the age of thirteen, working through Indian calculation, Euclid and the algebra of al-Karaji.

At about nineteen he wrote al-Bahir fi'l-jabr, the Brilliant in Algebra, which develops the arithmetic of polynomials, gives a table of binomial coefficients up to the twelfth power, and argues several results by a procedure recognised today as an early form of mathematical induction. He set out rules for the signs in multiplying negative quantities and worked with the division of polynomials and with decimal approximations of irrational numbers.

He also practised as a physician, wrote on astronomy and on medicine, and was influenced by the Jewish-born philosopher Abu al-Barakat al-Baghdadi. He died at Maragha about 1175.