Lösung 3.3:1c

Aus Online Mathematik Brückenkurs 2

The calculation follows a fairly set pattern. We write the number 43−4i  in polar form and then use de Moivre's formula.

This gives

43−4i=8cos−6+isin−6 

and then we get, on using de Moivre's formula,

43−4i22=822cos22−6+isin22−6=2322cos−311+isin−311=2322cos−312−+isin−312−=266cos−4+3+isin−4+3=266cos3+isin3=26621+i23=2651+i3