- TeX source:
- \begin{array}{crclcl} & \mathbb{D} &=& \mathbb{R} \cr\cr & 0 &=& \left(-\pi-k^2+x^2\right)\left(x^2-\pi^2-kx^2+k^2\pi^2\right) &\vert& \text{Satz vom Nullprodukt} \cr \text{Faktor 1:} & -\pi-k^2+x^2 &=& 0 &\vert& +\pi+k^2 \cr & x^2 &=& \pi+k^2 &\vert& \pm\sqrt{} \cr & x_{1,2} &=& \pm\sqrt{\pi+k^2} \end{array}