TeX Quellcode:

\begin{array}{rcl}f'(x) & = & \dfrac{1}{2} \cdot x^{\frac{1}{2}-1} \\\\ &=& \dfrac{1}{2} \cdot x^{-\frac{1}{2}} = \dfrac{1}{2x^{\frac{1}{2}}} = \dfrac{1}{2\sqrt{x}} \end{array}