Section 10.4 – Determinant of a SQUARE Matrix With and Without 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. + - + -

Section 10.4.2 – Determinant of a SQUARE Matrix Calculator Required

Enter the following matrices into your calculator:

Using your calculator, compute each of the following: 2nd Matrix -> 1 2nd Matrix 1

Right Arrow to see the rest

the matrix marked by the arrow Clearing the Matrices on the Calculator Now press DEL to delete the matrix marked by the arrow