Yoshida Mitsuyoshi (吉田光由)
Mitsuyoshi YOSHIDA (1598-1673) was a Japanese mathematician in the early Edo period.
Career
He was a member of a wealthy merchant, the Suminokura family. He called himself Kyuan. Ryoi SUMINOKURA was his maternal grandfather. He studied under the first Japanese mathematician, Shigeyoshi MORI. Later on, he studied a Chinese mathematics book, "Sanpo Toso" under his relative, Soan SUMINOKURA, and published his book, "Jinkoki" (a mathematical book covering almost all important mathematics useful for daily professional life in the Edo period) in 1628. The book was appraised for being an example of the introductory textbook of mathematics, which contained a lot of graphics and was written as to facilitate learning of the all level from the basics to the advanced level. In his later life, he lost his sight, then passed away at the age of 75 in 1672.