Question

2、设A为4阶矩阵,|A|=1/4 ,求,|3A^-1-4A*|= .

Answer 1

注意 A 是 4 阶矩阵,故

|3A^(-1)-4A*|

= |3A^(-1)-4[A^(-1)]|A||

= |[3-4(1/4)]A^(-1)|

= (2^4)*|A^(-1)|

= (2^4)*4

= 64