TeX Quellcode:

\begin{array}{rcl} f'_{zx}(x,y,z) &=& -\dfrac{20\pi x\sin\left(7y^5\right)\cdot e^{10xz+1} - 10\pi x^2\sin\left(7y^5\right)e^{10xz+1}\cdot 10z}{\left(e^{10xz+1}\right)^2} \\\\&=& -\dfrac{\left(20\pi x-10\pi x^2\cdot 10z\right)\sin\left(7y^5\right)e^{10xz+1}}{\left(e^{10xz+1}\right)^2} \\\\&=& \dfrac{\left(100\pi x^2z-20\pi x\right)\sin\left(7y^5\right)}{e^{10xz+1}}\end{array}