討論:三次平面曲線

本條目頁依照頁面品質評定標準被評為初級。
本條目頁屬於下列維基專題範疇：

（獲評初級、中重要度）

	數學主題閱論編本條目頁屬於數學專題範疇，該專題旨在改善中文維基百科數學類內容。如果您有意參與，請瀏覽專題主頁、參與討論，並完成相應的開放性任務。
初	根據專題品質評級標準，本條目頁已評為初級。
中	根據專題重要度評級標準，本條目已評為中重要度。

本條目有內容譯自英語維基百科頁面「Cubic plane curve」（原作者列於其歷史記錄頁）。

未翻譯內容[編輯]

首段未翻譯的內容如下

A cubic curve may have a singular point（英語：Singular point of an algebraic variety）, in which case it has a parametrization in terms of a projective line（英語：projective line）. Otherwise a non-singular cubic curve is known to have nine points of inflection, over an algebraically closed field such as the complex numbers. This can be shown by taking the homogeneous version of the Hessian matrix, which defines again a cubic, and intersecting it with C; the intersections are then counted by Bézout's theorem. However, only three of these points may be real, so that the others cannot be seen in the real projective plane by drawing the curve. The nine inflection points of a non-singular cubic have the property that every line passing through two of them contains exactly three inflection points. --Wolfch (留言) 2017年12月6日 (三) 19:29 (UTC)[回覆]