A C为对角矩阵行列式时,det([A B;C D]）的值是否与行列式det(A)*det(D)-det(B)*det(C)是相等的.因为det([A B;C D]=det(A)*det(D)-det(B)*det(C)的充要条件是
AC=CA,当A,C都是对角矩阵时,一定有AC=CA.