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

In 1706, Takebe was offered a position in the Tokugawa shogunate's department of ceremonies.

Legacy Takebe played a critical role in the development of the Enri (, "circle principle") - 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.

Takebe Prizes In the context of its 50th anniversary celebrations, the Mathematical Society of Japan established the Takebe Prize and the Takebe Prizes for the encouragement of young people who show promise as mathematicians.

1683 – OCLC 22056510086 1685 – OCLC 22056085721