Zero and identity matrices

4 videos
In arithmetic, we learned than a number times 1 is still that number and that anything times 0 is 0. In this tutorial, we attempt to extend these ideas to the world of matrices!

Introduction to the identity matrix

VIDEO 7:59 minutes
Just as any number remains the same when multiplied by 1, any matrix remains the same when multiplied by the identity matrix. Learn more from Sal.

Dimensions of identity matrix

VIDEO 3:44 minutes
Sal explains why the identity matrix is always a square matrix, even though it works with non-square matrices.

Introduction to the zero matrix

VIDEO 4:42 minutes
Just as any number multiplied by zero is zero, there is a zero matrix such that any matrix multiplied by it results in that zero matrix. Learn more from Sal.

Working with identity and zero matrices (example)

VIDEO 3:58 minutes
Sal solves a problem where he has to determine whether unknown matrices are zero or identity to make an equation true.