Lecture 21 Recording

We see that elementary row operations can be implemented by matrix multiplication and then we explain how performing the Gaussian elimination algorithm on a matrix naturally leads to an LU factorization of it -- provided you don't swap any rows and you only ever add scalar multiples of a row to rows below it! We then show a "trick" for writing down L from the list of row operations that you perform in order to put your matrix in echelon form.