Question 10
Soit \(\displaystyle z=\frac{2\,\mathrm{i}^9-4\, \mathrm{i}^{15}}{1-\mathrm{i}}\). Alors:
  • \(z^6=8\cdot 3^6\, \mathrm{i}\)
  • \(z^6=8\cdot 3^6\)
  • \(z^6=8\cdot3^6(1+\mathrm{i})\)
  • \(z^6=-8\cdot 3^6\,\mathrm{i}\)