Referring to last video in week 2 : The Gaussian Elimination Algorithm,
I think one of the updates to the matrix is incorrect at this point. Please can you double check and let me know.
Before starting the back substitution the matrix looks like this
Then after the first back substitution where pivot is 1 in row 3, you do row2 = row2 - row3 and row1 = row1 -1/2row3 you get this matrix
At this step I think row2 should look like
and not
Yes, you’re right, but note that the error is temporary. It first happens at about 5:33 and then as he rewrites it after simplifying the first line, the second line is correct again at timestamp 5:46 or thereabouts:
So the error only lasts for 13 seconds or so, but I’ll check to see if there is a bug filed about that and file one if it isn’t already noted. Thank you for noticing and reporting this.
There was not a bug filed yet about this, so I just filed it …
Thank you, got it
