# Determinant of a 3x3 Matrix

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Videos, worksheets, games and activities to help Algebra students learn how to find the determinant of a 3x3 matrix.

How to evaluate a determinant using row operations?
How to calculate the determinant using the diagonal method and cofactor method?

3x3 Determinant
Methods for computing a 3x3 determinant are important and are used when defining the cross product. Finding a 3x3 determinant is not as computationally heavy as finding the determinant of a larger square matrix. However, finding this determinant is more complicated than finding a 2x2 determinant. Using methods for simplifying determinants through row operations can make finding the 3x3 determinant much simpler.

Evaluating a Determinant Using Elementary Row Operations
 Row Operation Effect on Determinant Interchange two rows Change the sign Multiply a row by a constant Multiply by that constant Add a multiple of a row to another row No change
This video shows how to evaluate 2x2 and 3x3 determinants using the diagonal method and cofactor method.

This video provides an example of how to calculate the determinant using the diagonal method.
This video provides an example of how to calculate the determinant using the diagonal method

This video provides an example of how to calculate the determinant using the cofactor method.
This video provides an example of how to calculate the determinant using the cofactor method.

Finding the Determinant of a 3 x 3 matrix.
This video shows the basic formula and compute the determinant of a specific matrix.

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