#latex formula
\begin{eqnarray*}
        \|v\| & = & \sqrt{v^2_1 + v^2_2 + + v^2_n} = \sqrt{\sum_{i=1}^n{v^2_i}}\\
        K & = & \begin{cases}
                1 & \textrm{falls } \|v\| = 0 \\
                1 & \textrm{falls } \|v\| = \sqrt{n} \\
                0 & \textrm{sonst}
        \end{cases}
\end{eqnarray*}