How did Chinese mathematicians Jia Xian and Yang Hui study Pascalâs triangle before Blaise Pascal?
The triangular arrangement of numbers commonly known as Pascalâs triangle was studied in China centuries before Blaise Pascal.
In the 11th century, the mathematician Jia Xian devised this triangular representation to determine binomial coefficients for equations up to the sixth degree. He utilized this triangle in connection with his methods for extracting the roots of polynomials.12
In the 13th century, Yang Hui further studied and popularized Jia Xianâs work. In his 1261 treatise, Xiangjie jiuzhang suanfa, Yang Hui included a representation of the triangle, explicitly noting in the preface that he had copied it from Jia Xianâs earlier work. Because of Yang Hui's efforts to document and disseminate the method, the triangle is often referred to as the Yang Hui triangle in China. By the time it appeared in Zhu Shijieâs 1303 work, Siyuan yujian, the diagram was already referred to as the "Old Method," indicating its established place in Chinese mathematical tradition.13