1. Section 3.2 – Determinant of a SQUARE Matrix
No Calculator

2. Vocabulary First (Again  )
Determinant – a number (scalar)
Notations
The 2 x 2 Determinant

3. Try these four…
…and these four

4. The MINOR of a matrix
Cross out the row and column of the element
Compute the determinant of what remains

5. 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. –

6. –
– –
– –

7. – – –
= 0

8. Show the initial expansion of the determinant below by using the
second row.

9. Show the initial expansion of the determinant below by using the
third column.