TeX Quellcode:

\begin{array}{rcl} f'_{ab}(a,b,c) &=& 16a\cdot\left(-\dfrac{1}{2}\right)\left(16a^2-b^2+25c^2\right)^{-\frac{1}{2}-1}\cdot (-2b) \\\\&=& 16ab\left(16a^2-b^2+25c^2\right)^{-\frac{3}{2}} \\\\ &=& \dfrac{16ab}{\left(16a^2-b^2+25c^2\right)^{\frac{3}{2}}} \\\\&=& \dfrac{16ab}{\left(\sqrt{16a^2-b^2+25c^2}\right)^3}\end{array}