題組內容

2 Let $A = \begin{bmatrix} 1 & 0 & 2 \\ 0 & 1 & 1 \\ 1 & 2 & 4 \end{bmatrix}$ and $\mathbf{b} = \begin{bmatrix} 1 \\ -1 \\ 5 \end{bmatrix}$.

a. (6) Find the projection of \( \mathbf{b} \) onto the column space of \( A \).