TeX Quellcode:

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