2x22x2 matrices determinant Calculator tool

Diagonal lineun fold：

|a1 b1| =a1b2-a2b1

|a2 b2|

|a1 b1 c1|

|a2 b2 c2|=a1b2c3+b1c2a3+c1a2b3-a3b2c1-b3c2a1-c3a2b1

|a3 b3 c3|