3x3二阶矩阵行列式计算器
对角线展开:
|a1 b1| =a1b2-a2b1
|a2 b2|
|a1 b1 c1|
|a2 b2 c2|=a1b2c3+b1c2a3+c1a2b3-a3b2c1-b3c2a1-c3a2b1
|a3 b3 c3|