## Precalculus (6th Edition) Blitzer

The magnitude of a linear combination of the vector is calculated as, $\left\| \mathbf{v} \right\|=\sqrt{{{a}^{2}}+{{b}^{2}}}$ Here, a is the horizontal component of $\mathbf{v}$ and b is the vertical component of $\mathbf{v}$. The next step is: \begin{align} & \left\| \mathbf{v} \right\|=\sqrt{{{2}^{2}}+{{3}^{2}}} \\ & =\sqrt{4+9} \\ & =\sqrt{13} \end{align} Thus, the magnitude of the vector is $\sqrt{13}$.