Note Set 16d: How $\mathbf{A}=\mathbf{Q}\mathbf{R}$ helps us solve $\mathbf{A}\vec{x}=\vec{b}$
If we have the factorization $\mathbf{A}=\mathbf{Q}\mathbf{R}$ in a box, we can unpack $\mathbf{A}\vec{x}=\vec{b}$ in an enjoyable way. We explain how we're really solving the normal equation.
Best consumed by 2016/10/26