TeX Quellcode:

{ \left(\cos(\pi) + i \sin(\pi)\right) \cdot 7 \left( \cos(\pi)+i \sin(\pi) \right) \; = \; 7(\cos(\pi+\pi)+i\sin(\pi+\pi)) \; = \; 7(\cos(2\pi)+i\sin(2\pi)) \; = \; (7 \; ; \; 0) }