TeX Quellcode:

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