TeX Quellcode:
\begin{array}{rcl} \left|\lambda\left(-\dfrac{4}{5}\right) \begin{pmatrix}15 \cr -\frac{5}{12} \cr 0\end{pmatrix}\right| &=& \sqrt{\left(-\dfrac{4}{5} \cdot 15 \lambda\right)^2 + \left(-\dfrac{4}{5}\cdot\left(-\dfrac{5}{12}\right)\lambda\right)^2+ \left(-\dfrac{4}{5} \cdot 0\cdot \lambda\right)^2} \cr &=& \sqrt{\lambda^2 \left(144+ \dfrac{1}{9} +0\right)} \cr &=& \left|\lambda\right|\sqrt{\dfrac{1.297}{9}} \end{array}