TeX Quellcode:

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