Khan Academy: More Determinant Depth: Determinant After Row Operations

A video lesson explaining the determinant rule for the very special case when three matrices are identical except for one row, and that row of the third matrix is the sum of those rows in the other two matrices.

Correction of last video showing that the determinant when one row is multiplied by a scalar is equal to the scalar times the determinant

A video lesson proving that the determinant of an upper triangular matrix is the product of the all of the entries along the main diagonal

Video demonstrating that the area of a parallelogram that is the image of a rectangle under a transformation is equivalent to the absolute value of the determinant of the matrix whose column vectors generate the parallelogram.

A video lesson proving that if a matrix has duplicate rows then its determinant will be 0.

This video, shows how to calculate a 4x4 determinant by putting in in upper triangular form first.

This video demonstrates the order of operations in a numerical expression. Practice problems are available. [9:40]

This video explains the order of operations with exponents and negative numbers. Practice problems are available. [4:36]

Sal dives in even deeper with a few more examples of exponential decay. Practice calculating k from half-life, and calculating initial mass. [7:21]

A video lesson describing how the determinants for larger matrices can be found using cofactor expansion on any row or column. Illustrates that it is helpful to choose rows or columns with zeros in order to simplify the computations....