TeX Quellcode:

\dfrac{4}{7} \, e^{i \frac{5\pi}{6}} \; \cdot \; \dfrac{21}{8} \, e^{i \, \frac{2\pi}{3}} \; = \; \dfrac{4}{7} \, \cdot \, \dfrac{21}{8} \, e^{i \, \left(\frac{5\pi}{6}+\frac{2\pi}{3}\right)} \; = \; \dfrac{3}{2} \, e^{i \, \frac{3\pi}{2}} \; = \; -\dfrac{3}{2} i