Omar Khayyám (1048–1131) is not well-known for math, but for being immortalized by Edward FitzGerald, the nineteenth century English poet who translated Khayyám’s own 600 short four line poems, the Rubaiyat. (However, FitzGerald’s translations were not exact—and most scholars agree that Khayyám did not state, “a jug of wine, a loaf of bread, and Thou.” Those words were actually conceived by FitzGerald.)

In reality, Khayyám was actually known as al-Khayyámi, the Persian mathematician, poet, and astronomer whose contributions were many. He wrote the Treatise on Demonstration of Problems of Algebra, a book that contains a complete classification of cubic equations with geometric solutions—all found by means of intersecting conic sections. He solved the general cubic equation hundreds of years before Niccoló Tartaglia in the 16th century, but his work only had positive roots, since it was completely geometrical (see this chapter for more about Tartaglia). He also calculated the length of the year to be 365.24219858156 days—a remarkably accurate result for his time—and proved that algebra was definitely related to geometry.