Finding the line of best fit with linear algebra

The line of best fit is easy to find. This video explains why the method works using a theorem from linear algebra.

[dalisabe]

The matrix A should be the transpose of what he set it up to be. Otherwise Ax is undefined. Nevertheless, we get the idea and it’s quite brilliant that linear algebra could do the trick of the calculus method without appealing to the concept of minima and maxima by setting the derivative of the function to zero. Thanks.

[jackhu]

I believe that at point 4:59 he intended to have a Col(A)⊥ instead of the transpose of the column space which does not make sense

[samuelatienzo]

5:42 - "...and at this point, Robert is your father's brother..." = "Bob's your uncle?" :')