Seki Kōwa

Seki Takakazu (Seki Kōwa)
Seki Takakazu (Seki Kōwa)
Born	March(?), 1642(?) Edo or Fujioka, Japan
Died	December 5, 1708 (Gregorian calendar) Japan
Residence	Japan
Nationality	Japanese
Fields	Mathematics

Seki Takakazu (関 孝和, 1642 – December 5, 1708), also known as Seki Kōwa (関 孝和), was a Japanese mathematician in the Edo period.

Seki laid foundations for the subsequent development of Japanese mathematics known as wasan; and he has been described as "Japan's Newton".

He created a new algebraic notation system and, motivated by astronomical computations, did work on infinitesimal calculus and Diophantine equations. A contemporary of Gottfried Leibniz and Isaac Newton, Seki's work was independent. His successors later developed a school dominant in Japanese mathematics until the end of the Edo period.

While it is not clear how much of the achievements of wasan are Seki's, since many of them appear only in writings of his pupils, some of the results parallel or anticipate those discovered in Europe. For example, he is credited with the discovery of Bernoulli numbers. The resultant and determinant (the first in 1683, the complete version no later than 1710) are attributed to him. This work was a substantial advance on, for example, the comprehensive introduction of 13th-century Chinese algebra made as late as 1671, by Kazuyuki Sawaguchi.

Not much is known about Kōwa's personal life. His birthplace has been indicated as either Fujioka in Gunma prefecture, or Edo. His birth date ranges from 1635 to 1643.

He was born to the Uchiyama clan, a subject of Ko-shu han, and adopted into the Seki family, a subject of the Shogun. While in Ko-shu han, he was involved in a surveying project to produce a reliable map of his employer's land. He spent many years in studying 13th-century Chinese calendars to replace the less accurate one used in Japan at that time.