How To - Determinants of Matrices
There are three basic cases for matrices, dimensions 2x2, 3x3 and dimensions 3<.
Results for the three exercises will be posted at the end.
Tipp: a matrix can only be inverted if the determinant does not equal 0 !
In the case of matrix A (2x2) the main- minus minor-diagonal formula applies; with upper left times lower right, minus upper right times lower left.
For example B (3x3) it becomes more complicated. We can apply the rule of Sarrus (Wikipedia). For that, we replicate the first two columns to the right side. Now we create the main and minor diagonals, as seen in the picture below: