TeX Quellcode:

\begin{array}{rcl}\mathbb{D}&=&\mathbb{R}\setminus_{\{0\}} \cr \cr f(x) &=& -\dfrac{1}{12} \cdot x^{-3} \cr\cr\cr f'(x) &=& -\dfrac{1}{12} \cdot \left(-3\right) \cdot x^{-3-1} \cr\cr &=& \dfrac{1}{4}x^{-4} \cr\cr &=& \dfrac{1}{4x^4} \end{array}