Answer
$\frac{2}{\sqrt{5}}\mathbf{i}-\frac{1}{\sqrt{5}}\mathbf{j}$
Work Step by Step
Therefore,
$\begin{align}
& \left\| \mathbf{v} \right\|=\sqrt{{{4}^{2}}+{{\left( -2 \right)}^{2}}} \\
& =\sqrt{20} \\
& =2\sqrt{5}
\end{align}$
So,
$\begin{align}
& \frac{\mathbf{v}}{\parallel \mathbf{v}\parallel }=\frac{4}{2\sqrt{5}}\mathbf{i}-\frac{2}{2\sqrt{5}}\mathbf{j} \\
& =\frac{2}{\sqrt{5}}\mathbf{i}-\frac{1}{\sqrt{5}}\mathbf{j}
\end{align}$