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034向量及反對稱陣常用運算規則

有向量 a , b , c a, b, c 及其反對稱矩陣 A ,

B , C A, B, C ,單位陣 I I ,常用以下運算規則

1、點積

a

b = b a = a T
b = b T a a \cdot b = b \cdot a = a^T b = b^T a

2、叉積

a × b = A b = b × a = B a a × b = Ab = -b × a = -Ba

3、常用關係式

A a = a × a = 0 Aa = a × a = 0
( a × b ) = ( A b ) = A B B A (a × b)^* = (Ab)^* = AB - BA
A B = b a T b T a I AB = ba^T - b^T a I
( a × b ) c = a ( b × c ) = a T B c (a × b) \cdot c = a \cdot (b × c) = a^TBc
a × ( b × c ) = A B c a × (b × c) = ABc
( a × b ) × c = ( A b ) c = ( A B B A ) c = A B c B A c (a × b) × c = (Ab)^*c = (AB-BA)c=ABc-BAc

^* 表示相應向量的反對稱矩陣