设A是4阶方阵,且行列式|A|=8,B=-1/2A,求|B|

题目

设A是4阶方阵,且行列式|A|=8,B=-1/2A,求|B|

答案

|kA| = k^n|A|
|B| = |-1/2A| = (-1/2)^4 |A| = 2^(-4+3) = 1/2