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