Example:

Going back to our simple 2D example $x=[2, 3]$, we can compute its norm as $\Vert x\Vert = \sqrt{2^2 + 3^2} = \sqrt{13} = 3.6056\ldots\,$. The physical interpretation of the norm as a distance measure is shown in Fig.5.5.

Figure 5.5: Geometric interpretation of a signal norm in 2D.

Figure 5.6: Length of vectors in sum.