# Determinant of a 4x4 matrix

Last updated: Jan. 2nd, 2019
Find the determinant of a 4x4 matrix

### Explanation

The cofactor expansion of $A$ along the first column is

Calculating the 3x3 determinant in each term,
From these, we obtain
Example:
Find the determinant of
as in the above method.
The cofactor expansion of $A$ along the first column is
Calculating the 3 by 3 determinant in each term,
We obtain
Calculator
Enter a 4x4 matrix and press "Execute" button. Then the determinant is displayed.
 1 2 3 4 1 2 3 4
$|A| \hspace{2mm} = \hspace{2mm}$