Jamshid al-Kashi of Samarkand

Jamshid al-Kashi of Samarkand (c. 1380 – 22 June 1429) was an Arab mathematician and astronomer. Noteworthy for the accuracy of his computations, especially in connection with the solution of equations by Horner’s method and his practice of using decimal fractions, both of which he derived from the Chinese.

Al-Kashi paid special attention to the method of measuring the parts of edifices and building such as arches, vaults, hollow, cupolas and stalactite surfaces widely wonted in the medieval East.

Calculated correctly π to 16 decimal places, No mathematician approached this accuracy until the late 16th century.

Between the 14th and the 15th century, Al-Kashi wrote the Key to Arithmetic. In this work he calls binomial coefficients “exponent elements”. The book provides a glimpse of the influence of Chinese mathematics.

Al-Kashi found patron in the prince Ulugh Beg, grandson of the Mongol conqueror Tamerlane. At Samarkand, where he held his court, Ulugh Beg had built an observatory in 1428 and al-Kashi joined the group of scientist gathered there.
Jamshid al-Kashi of Samarkand