Takebe Kenkō
Takebe Katahiro, also known as Takebe Kenkō, was a Japanese mathematician and cartographer during the Edo period.
Biography
Takebe was the favorite student of the Japanese mathematician Seki Takakazu Takebe is considered to have extended and disseminated Seki's work.In 1706, Takebe was offered a position in the Tokugawa shogunate's department of ceremonies.
In 1719, Takebe's new map of Japan was completed; and the work was highly valued for its quality and detail.
Shōgun Yoshimune honored Takebe with rank and successively better positions in the shogunate.
Legacy
Takebe played a critical role in the development of the Enri - a crude analogon to the western calculus. He also created charts for trigonometric functions.He achieved a power series expansion of in 1722, 15 years earlier than Euler.
This was the first power series expansion obtained in Wasan. This result was first conjectured by heavy numeric computation.
He used the Richardson extrapolation in 1695, about 200 years earlier than Richardson.
He also computed 41 digits of, based on polygon approximation and the Richardson extrapolation.