Algebra · a Light

He wrote his algebra book at nineteen

Al-Samawal was born in Baghdad to a Jewish family from Morocco. He worked through the mathematics available in the city, found by his late teens that he had exhausted it, and wrote al-Bahir, the Brilliant, at about nineteen. In it he divided one polynomial by another by setting the coefficients out in a table, which is the long division of algebra, stated the laws of exponents including the negative ones, and recorded that any quantity raised to the power zero is one. He used repeated division to carry a quotient to as many places as he wanted, coming close to the idea of an unending decimal. He became a Muslim in 1163 and wrote his own account of why. He died around 1180 at Maragha.

Al-Samawal al-Maghribi · Baghdad, c. 1130-1180