High-powered equations with one unknown variable were introduced in the tang dynasty , and their use was greatly expanded during the song , jin , and yuan dynasties , and a method of numerical analysis (the horner scheme , which was introduced by horner in nineteenth century ) of high-powered equations with one unknown variable for ordinary real numbers and coefficients was discovered . 唐のころから一元高次方程式を扱い始め、宋金元の時代に大いに発展し、一般の実数係数の一元高次方程式の数値的解法(ホーナー法、ホーナーによる提唱は19世紀)を見出した。