Find the norm of $\vec{x}$ and the unit vector $\vec{u}$ in the direction of $\vec{x}$ if $$\vec{x} = \left[\begin{array}{c} -3\cr 1\cr -3\cr 3 \end{array}\right].$$
$\| \vec{x} \| =$ ,

$\vec{u} =$ $\left[\Rule{0pt}{4.8em}{0pt}\right.$$\left]\Rule{0pt}{4.8em}{0pt}\right.$