Chapter 6.3, Problem 9E

In Exercises 7–10, let W be the subspace spanned by the u’s, and write y as the sum of a vector in W and a vector orthogonal to W.

9. y = $\left[\begin{array}{c}4\\ 3\\ 3\\ -1\end{array}\right]$, u₁ = $\left[\begin{array}{c}1\\ 1\\ 0\\ 1\end{array}\right]$, u₂ = $\left[\begin{array}{c}-1\\ 3\\ 1\\ -2\end{array}\right]$, u₃ = $\left[\begin{array}{c}-1\\ 0\\ 1\\ 1\end{array}\right]$