TeX Quellcode:

\begin{array}{rcl}z_1 \cdot z_2 &=& \dfrac{1}{2}e^{i\,\frac{5\pi}{4}}\cdot 10e^{i\,\frac{\pi}{6}} \\ \\ &=& \dfrac{1}{2}\cdot 10e^{i\,\frac{5\pi}{4}+i\,\frac{\pi}{6}} \\ \\ &=& 5e^{i\,\frac{17\pi}{12}}\end{array}