Algebra · a Light

Khayyam solved cubic equations by crossing two curves

Omar Khayyam is read in English as a poet, on the strength of a loose Victorian version of verses attributed to him. In Persian and Arabic he is a mathematician. Around 1070 he wrote a treatise sorting cubic equations into fourteen kinds that cannot be reduced to anything simpler, and giving each kind a solution by drawing two conic sections, a circle with a parabola or a hyperbola, and measuring where they cross. He said plainly that he had found no way to solve them by arithmetic and hoped somebody would. Somebody did, in Italy, four and a half centuries later. He also led the committee that produced the Jalali solar calendar, and wrote on the parallel postulate that troubled geometers until the nineteenth century.

Omar Khayyam · Samarkand and Isfahan, c. 1070