TeX Quellcode:

\begin{array}{rcl} f'_{xz}(x,y,z) &=& 150\cdot \left(-\dfrac{1}{2}\right)(x+yz)^{-\frac{1}{2}-1}\cdot y \\\\&=& -75y(x+yz)^{-\frac{3}{2}} \\\\ &=& -\dfrac{75y}{\left(\sqrt{x+yz}\right)^3} \end{array}