(

fl. ''Floruit'' ( ; usually abbreviated fl. or occasionally flor.; from Latin for 'flourished') denotes a date or period during which a person was known to have been alive or active. In English, the unabbreviated word may also be used as a noun indic ...

830), known also as () was a ninth-century

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

. Not much is known about his life. The two records of him, one by Ibn Nadim and the other by al-Qifti are not identical. Al-Qifi mentions his name as ʿAbd al-Hamīd ibn Wase ibn Turk al-Jili. Jili means from Gilan. On the other hand, Ibn Nadim mentions his nisbah as ''khuttali'' (), which is a region located north of the Oxus and west of Badakhshan. In one of the two remaining manuscripts of his ''al-jabr wa al-muqabila'', the recording of his nisbah is closer to ''al-Jili''.Ibn Turk
in ''Dāʾirat al-Maʿārif-i Buzurg-i Islāmī'', Vol. 3, no. 1001, Tehran. To be translated in Encyclopædia Islamica.

David Pingree David Edwin Pingree (January 2, 1933 – November 11, 2005) was an American historian of mathematics in the ancient world. He was a University Professor and Professor of History of Mathematics and Classics at Brown University. Life Pingree gra ...

/ ''

Encyclopaedia Iranica An encyclopedia is a reference work or compendium providing summaries of knowledge, either general or special, in a particular field or discipline. Encyclopedias are divided into articles or entries that are arranged alphabetically by artic ...

'' states that he originally hailed from Khuttal or Gilan. He wrote a work on

algebra Algebra is a branch of mathematics that deals with abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic ope ...

entitled ''Logical Necessities in Mixed Equations'', which is very similar to al-Khwarzimi's ''Al-Jabr'' and was published at around the same time as, or even possibly earlier than, ''Al-Jabr''. Only a chapter called "Logical Necessities in Mixed Equations", on the solution of

quadratic equations In mathematics, a quadratic equation () is an equation that can be rearranged in standard form as ax^2 + bx + c = 0\,, where the variable (mathematics), variable represents an unknown number, and , , and represent known numbers, where . (If and ...

, has survived. The manuscript gives exactly the same geometric demonstration as is found in ''Al-Jabr'', and in one case the same example as found in ''Al-Jabr'', and even goes beyond ''Al-Jabr'' by giving a geometric proof that if the

discriminant In mathematics, the discriminant of a polynomial is a quantity that depends on the coefficients and allows deducing some properties of the zero of a function, roots without computing them. More precisely, it is a polynomial function of the coef ...

is negative then the quadratic equation has no solution. The similarity between these two works has led some historians to conclude that algebra may have been well developed by the time of al-Khwarizmi and 'Abd al-Hamid.

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* Mathematicians of the medieval Islamic world Mathematicians from the Abbasid Caliphate 9th-century mathematicians 9th-century people from the Abbasid Caliphate Year of birth unknown Year of death unknown {{asia-mathematician-stub

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Further reading

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