(後只人季 定义2.10:设A为矩阵A=anl的行列式4中元 素a的代数余子式,则称 1 nI A12A2 为A的伴随矩阵,记为A*或者adjA 由于∑akAk=∑a4 0i≠ A A*A=AA= =AE11 21 1 12 22 2 1 2 * n n n n nn A A A A A A A A A A     =         1 1 0 n n ik jk ki kj k k A i j a A a A = = i j  = = =    由于   | | | | * * | | | | A A A A AA A E A     = = =        