Ajima Naonobu

Ajima Naonobu (1732 to 20 May 1798), also known as Ajima Manzo Chokuyen, was a Japanese mathematician of the Edo period. He is credited with introducing calculus into Japanese mathematics, although the significance of this is diminished by the likelihood that he had access to European writings on the subject. He also posed the problem of inscribing three mutually tangent circles in a triangle; those circles are now called Malfatti circles after the later work of Gian Francesco Malfatti, but two triangle centers derived from them, the Ajima-Malfatti points, bear Ajima's name. He worked as an astronomer at the Shogun's Observatory, and in 1976 the International Astronomical Union named a lunar crater, Naonobu, after him.