Jia Xian

Jia Xian

(flourished c. 1050, China) Mathematician and astronomer active at the beginning of the greatest period of traditional Chinese mathematics. He held a relatively low military office during the reign (1022/23–1063/64) of Emperor Renzong of the Song dynasty. He was a pupil of mathematician and astronomer Chu Yan, who contributed to the revision of the Chongtian calendar in 1023, and he served in the Imperial Astronomical Bureau. Jia's name was mainly quoted in connection with his method of extracting roots (solutions) of polynomials of degree higher than three and with the related Jia Xian triangle, which contains the binomial coefficients for equations up to the sixth degree (see binomial theorem). This diagram is similar to Blaise Pascal's triangle, which was discovered independently later in the West.