# Albert Girard

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**Albert Girard**was a French-born*mathematician*. He studied at the University of Leiden. He "had early thoughts on the fundamental theorem of algebra" and gave the inductive definition for the Fibonacci numbers. He was the first to use the abbreviations 'sin', 'cos' and 'tan' for the trigonometric functions in a treatise. Girard was the first to state, in 1632, that each prime of the form 1 mod 4 was the sum of two squares. It was said that he was quiet-natured and, unlike most mathematicians, did not keep a journal for his personal life.- also known as Жирар, Альбер
- born in (420 years ago) in Saint-Mihiel
- nationality: France
- education: Leiden University
- profession: Mathematician
- died on (383 years ago) in Leiden

**Albert Girard**was a Progressive Conservative party member of the Canadian House of Commons. His background was in business.- born on (66 years ago)
- nationality: Canada

## Printed dictionaries and other books with definitions for Albert Girard

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### Historical Encyclopedia of Natural and Mathematical Sciences (2009)

by Ari Ben-Menahem

**Albert Girard** (1629) conjectured that an equation of degree n always has n
solutions in the domain of complex numbers. Attempts to prove this were made
by Descartes, d'Alembert and others, but it was only Gauss (1799) who
succeeded in ...

### The General Biographical Dictionary (1816)

Containing an Hist. and Crit. Account of the Lives and Writings of the Most Eminent Persons in Every Nation; Particularly the British and Irish; from the Earliest Accounts to the Present Time. Sim - Sty by Alexander Chalmers

There are also two editions in the French language, in folio, both printed at Ley
den, the one in 1608, and the other in 1634, with curious notes and additions, by
**Albert Girard**. In Dr. Hutton's Dictionary, art. Algebra, there is a particular account
...

### Companion Encyclopedia of the History and Philosophy of the Mathematical Sciences (2002)

by Ivor Grattan-Guinness

**Albert Girard** called complex roots
solutions impossibles, but nevertheless formulated the fundamental theoremof
algebra, whichstates roughly that a polynomial of degree n hasnroots. Although ...

### The British encyclopedia, or, Dictionary of arts and sciences (1809)

by William Nicholson

Vieta first used the bar or line over the quantities, for a vinculum, thus n -f- h ; and
**Albert Girard** the parenthesis, thus (a -\- b) ; the former way being now chiefly
used by the English, and the latter by most other Europeans. Thus a -f- b x c, or (
a ...

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