企源知识库

设A=
(12-1
310
10-2)
，求A^-1．
【正确答案】：A^-1=1/|A| (A¹¹ A²¹ A³¹ A¹² A²² A³² A¹³ A²³ A³³) =1/9 (-2 4 1 6 -3 -3 1 -2 -5) = (-(2/9) 4/9 1/9 2/3 -(1/3) -(1/3) 1/9 -(2/9) -(5/9))