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Weingarten equations give expansion of the derivative of the unit normal vector to a surface in terms of the first derivatives of the position vector of this surface. These formulas were established in 1861 by German mathematician Julius Weingarten. ==Statement in classical differential geometry== Let ''S'' be a surface in three-dimensional Euclidean space that is parametrized by position vector r(''u'', ''v'') of the surface. Let ''P'' = ''P''(''u'', ''v'') be a fixed point on this surface. Then : are two tangent vectors at point ''P''. Let n be the unit normal vector and let (''E'', ''F'', ''G'') and (''L'', ''M'', ''N'') be the coefficients of the first and second fundamental forms of this surface, respectively. The Weingarten equation gives the first derivative of the unit normal vector n at point ''P'' in terms of tangent vectors ru and rv: : : 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Weingarten equations」の詳細全文を読む スポンサード リンク
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