Section 3.2 – Determinant of a SQUARE Matrix No Calculator
Vocabulary First (Again ) Determinant – a number (scalar) Notations The 2 x 2 Determinant
Try these four… …and these four
The MINOR of a matrix Cross out the row and column of the element Compute the determinant of what remains
The 3 x 3 Determinant 1. Select ANY row or column (most zeros would be smart) 2. Take each element and multiply it by its MINOR. Apply + - + - + - (to be explained). Remember the + starts with the first row first column element. + – +
+ – + – + – – + –
– + – + – + = 0
Show the initial expansion of the determinant below by using the second row. - + - +
Show the initial expansion of the determinant below by using the third column. + - + -