Determinant of a 2 x 2 Matrix

Determinants of a 2 x 2 Matrix

To take the determinant of a [math]2\times2[/math] matrix, you multiply the top-left-to-bottom-right diagonal, and from this you subtract the product of bottom-left-to-top-right diagonal.

Remark

Determinants can be expanded using any one of the rows and columns.

Note:

Expansion of Determinant using first row only

[math]\Delta=_{ }a_{11}M_{11}-a_{12}M_{12}+a_{13}M_{13}[/math]

Information: Determinant of a 2 x 2 Matrix