TeX Quellcode:

\begin{array}{rclll} f(x) &=& \ln\left(\dfrac{1}{2}x^3-12x\right) -15\cr \cr f\left(-\sqrt{8}\right) &=& \ln\left(\dfrac{1}{2} \cdot \left(-\sqrt{8}\right)^3-12 \cdot \left(-\sqrt{8}\right)\right) &\approx& -11{,}88 \end{array}