Paper 1
Difficulty:Medium

Let $latex \vec{v}=\begin{pmatrix}

1\\

2\\

3

\end{pmatrix}$, and $latex \vec{w}=\begin{pmatrix}

-3\\

1\\

2

\end{pmatrix}$.

If $latex \vec{u}=\vec{v}-2\vec{w}$, find the magnitude of vector $latex \vec{u}$.

[Maximum mark:5]