What year was algebra introduced?

Answer 1

Early Greeks, such as Pythagoras and Euclid, relied on geometry to express all of their logical proofs. It was about 250 CE when the Greek Diophantus (from Alexandria) began using Greek letters as numbers and other mathematical symbols. He is sometimes called the father of algebra. Since this was not developed into a fully symbolic algebra on its own, it is called syncopated algebra.

Later, about 820 CE, the Muslims founded the House of Wisdom, a collection of many would-be lost Greek and Indian writings. Here, Al-Khwarizmi wrote Hisab al-jabr w'al-muqabala (Calculation by Restoration and Reduction). The word algebra comes from al-jabr. This algebra was still written out in story problems, but it was the great step away from depending on geometry for proofs.

Finally, algebra began to take on its modern symbolic look when Viéte used letters for variables around 1600. Then in 1637, Descartes wrote La géométrie. Before this, mathematicians had thought of polynomials spaically, so x3 actually represented a cube. His written algebra is the first to look almost exactly like ours. (Supposedly, upon printing, Descartes was asked if it mattered which letters were used for variables. He said no, resulting in x,y, and z since they were used least!)