3正交矩阵的判定AAE RnxnA =(a,) =(α1,α2,..,αn)=(β.)①A为正交矩阵 A=A-1[1, i= j,i, j =1,2,..,n②A为正交矩阵α'α,=[0, i ],[1, i=j,,j =1,2,,n③A为正交矩阵β,β=[0, i± j,国习题课正交矩阵的性质习题课 正交矩阵的性质 n n n A ai j n R                 = = =         2 1 1 2 ( ) ( , , , )    =  =  = i j n i j i j i j , 1,2, , 0, , 1, , ③ A为正交矩阵   '     =  =  = i j n i j i j i j , 1,2, , 0, , 1, , ② A为正交矩阵  '  1 ' − ① A为正交矩阵  A = A 3 正交矩阵的判定