Determinants of Matrices

Today we learned how to find the determinant of any square matrix.
It is fairly easy to find the determinant of a 2 x 2 matrix, where the determinant in the matrix
| w  x |
| y   z |
is wz - xy.
For a 3 x 3 matrix, several methods of finding the determinant can be used:

• You can use a shortcut in which the first two columns of the matrix are written to the right side of the last column of the matrix, and then diagonals are formed in order to individually subtract the products of the upward diagonals from those of the downward ones.
• You can use minors and cofactors to solve any square matrix n x n, and this method can be applied to a 3 x 3 matrix, where n = 3.
• If the matrix is triangular, you can find the product of the middle diagonal of the matrix, and this will be the determinant.

Below is an image of the practice problems from today's lesson, which I have completed in UPAD lite:

The following is a link to an Educreations video made in our group:

http://www.educreations.com/lesson/view/determinant-of-a-matrix/16850106/?s=ciem9G&ref=app