TeX Quellcode:

\begin{array}{rcl} \left|\lambda\begin{pmatrix}3\cr7\cr-1\end{pmatrix}\right| &=& \sqrt{{\left(3\lambda\right)}^2+{\left(7\lambda\right)}^2 +{\left(-\lambda\right)}^2} \cr &=& \sqrt{\lambda^2 \left(9+49+1\right)} \cr &=& \left|\lambda\right|\sqrt{59} \end{array}