Editing Chinese mathematics (section)

====''Ceyuan haijing''====
{{main|Ceyuan haijing}}
[[File:圆城图式.jpg|right|thumb|273x273px|Li Ye's inscribed circle in triangle:'''Diagram of a round town''']]
[[File:Yang_Hui_magic_circle.svg|thumb|[[Yang Hui]]'s magic concentric circles – numbers on each circle and diameter (ignoring the middle 9) sum to 138]]
''[[Ceyuan haijing]]'' ({{zh|t=測圓海鏡|p= Cèyuán Hǎijìng}}), or ''Sea-Mirror of the Circle Measurements'', is a collection of 692 formula and 170 problems related to inscribed circle in a triangle, written by [[Li Zhi (mathematician)|Li Zhi]] (or Li Ye) (1192–1272 AD). He used [[Tian yuan shu]] to convert intricated geometry problems into pure algebra problems. He then used ''fan fa'', or [[Horner's method]], to solve equations of degree as high as six, although he did not describe his method of solving equations.{{sfn|Boyer|1991|loc="China and India"|p=204}} "Li Chih (or Li Yeh, 1192–1279), a mathematician of Peking who was offered a government post by Khublai Khan in 1206, but politely found an excuse to decline it. His ''Ts'e-yuan hai-ching'' (''Sea-Mirror of the Circle Measurements'') includes 170 problems dealing with[...]some of the problems leading to polynomial equations of sixth degree. Although he did not describe his method of solution of equations, it appears that it was not very different from that used by Chu Shih-chieh and Horner. Others who used the Horner method were Ch'in Chiu-shao (ca. 1202 – ca.1261) and Yang Hui (fl. ca. 1261–1275).