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In a group, the conjugate by ''g'' of ''h'' is ''ghg''−1. ==Translation== If ''h'' is a translation, then its conjugate by an isometry can be described as applying the isometry to the translation: *the conjugate of a translation by a translation is the first translation *the conjugate of a translation by a rotation is a translation by a rotated translation vector *the conjugate of a translation by a reflection is a translation by a reflected translation vector Thus the conjugacy class within the Euclidean group ''E''(''n'') of a translation is the set of all translations by the same distance. The smallest subgroup of the Euclidean group containing all translations by a given distance is the set of ''all'' translations. Thus this is the conjugate closure of a singleton containing a translation. Thus ''E''(''n'') is a semidirect product of the orthogonal group ''O''(''n'') and the subgroup of translations ''T'', and ''O''(''n'') is isomorphic with the quotient group of ''E''(''n'') by ''T'': :''O''(''n'') ''E''(''n'') ''/ T'' Thus there is a partition of the Euclidean group with in each subset one isometry that keeps the origin fixed, and its combination with all translations. Each isometry is given by an orthogonal matrix ''A'' in ''O''(''n'') and a vector ''b'': : and each subset in the quotient group is given by the matrix ''A'' only. Similarly, for the special orthogonal group ''SO''(''n'') we have :''SO''(''n'') ''E''+(''n'') ''/ T'' 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「Conjugation of isometries in Euclidean space」の詳細全文を読む スポンサード リンク
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