TeX Quellcode:

\begin{array}{rcl} f'_{zx}(x,y,z) &=& \dfrac{y^2 e^{-3xy} +xy^2 e^{-3xy}\cdot (-3y)}{z}\\\\ &=& \dfrac{y^2 e^{-3xy}-3xy^3 e^{-3xy}}{z}\\\\&=& \dfrac{-3xy^3+y^2}{z} e^{-3xy}\end{array}