Mocniny a odmocniny komplexných čísel

9000035810

Časť: 
C
Je dané komplexné číslo \(z = -2 + 2\mathrm{i}\). Všetky navzájom rôzne hodnoty \(\root{3}\of{z}\) sú:
\(\begin{aligned}[t] &w_{0} = \root{6}\of{8}\left (\cos \frac{\pi } {4} + \mathrm{i}\sin \frac{\pi } {4}\right ) & \\&w_{1} = \root{6}\of{8}\left (\cos \frac{11\pi } {12} + \mathrm{i}\sin \frac{11\pi } {12}\right ) \\&w_{2} = \root{6}\of{8}\left (\cos \frac{19\pi } {12} + \mathrm{i}\sin \frac{19\pi } {12}\right ) \\ \end{aligned}\)
\(\begin{aligned}[t] &w_{0} = 2\left (\cos \frac{\pi } {4} + \mathrm{i}\sin \frac{\pi } {4}\right ) & \\&w_{1} = 2\left (\cos \frac{11\pi } {12} + \mathrm{i}\sin \frac{11\pi } {12}\right ) \\&w_{2} = 2\left (\cos \frac{19\pi } {12} + \mathrm{i}\sin \frac{19\pi } {12}\right ) \\ \end{aligned}\)
\(\root{3}\of{-2} + \root{3}\of{2}\)
\(\begin{aligned}[t] &w_{0} = 2\left (\cos \frac{\pi } {3} + \mathrm{i}\sin \frac{\pi } {3}\right )& \\&w_{1} = 2\left (\cos \pi +\mathrm{i}\sin \pi \right ) \\&w_{2} = 2\left (\cos \frac{5\pi } {3} + \mathrm{i}\sin \frac{5\pi } {3}\right ) \\ \end{aligned}\)

9000034301

Časť: 
B
Nájdite množinu všetkých riešení danej rovnice v množine komplexných čísel. \[ x^{3} - 1 = 0 \]
\(\{1;\ -\frac{1} {2} + \mathrm{i}\frac{\sqrt{3}} {2} ;\ -\frac{1} {2} -\mathrm{i}\frac{\sqrt{3}} {2} \}\)
\(\{1;\ -1 + \mathrm{i}\sqrt{3};\ -1 -\mathrm{i}\sqrt{3}\}\)
\(\{1;\ -\frac{1} {2} + \mathrm{i}\frac{\sqrt{3}} {2} \}\)
\(\{1;\ -\frac{1} {2} -\mathrm{i}\frac{\sqrt{3}} {2} \}\)

9000034302

Časť: 
B
Nájdite množinu všetkých riešení danej rovnice v množine komplexných čísel. \[ x^{3} + 8 = 0 \]
\(\{ - 2;\ 1 + \mathrm{i}\sqrt{3};\ 1 -\mathrm{i}\sqrt{3}\}\)
\(\{ - 2;\ -1 + \mathrm{i}\sqrt{3};\ -1 -\mathrm{i}\sqrt{3}\}\)
\(\{ - 2;\ \frac{1} {2} + \mathrm{i}\frac{\sqrt{3}} {2} ;\ \frac{1} {2} -\mathrm{i}\frac{\sqrt{3}} {2} \}\)
\(\{ - 2;\ -\frac{1} {2} + \mathrm{i}\frac{\sqrt{3}} {2} ;\ -\frac{1} {2} -\mathrm{i}\frac{\sqrt{3}} {2} \}\)

9000034303

Časť: 
C
Nájdite množinu všetkých riešení danej rovnice v množine komplexných čísel. \[ x^{3} + \mathrm{i} = 0 \]
\(\{\mathrm{i};\ \frac{\sqrt{3}} {2} -\frac{1} {2}\mathrm{i};\ -\frac{\sqrt{3}} {2} -\frac{1} {2}\mathrm{i}\}\)
\(\{ - 1;\ -\frac{\sqrt{3}} {2} + \frac{1} {2}\mathrm{i};\ -\frac{\sqrt{3}} {2} -\frac{1} {2}\mathrm{i}\}\)
\(\{ - 1;\ \frac{\sqrt{3}} {2} -\frac{1} {2}\mathrm{i};\ -\frac{\sqrt{3}} {2} -\frac{1} {2}\mathrm{i}\}\)
\(\{\mathrm{i};\ -\frac{\sqrt{3}} {2} + \frac{1} {2}\mathrm{i};\ -\frac{\sqrt{3}} {2} -\frac{1} {2}\mathrm{i}\}\)

9000034304

Časť: 
B
Nájdite množinu všetkých riešení danej rovnice v množine komplexných čísel. \[ x^{4} - 1 = 0 \]
\(\{1;\ -1;\ \mathrm{i};\ -\mathrm{i}\}\)
\(\{1 -\mathrm{i};\ -1 -\mathrm{i}\}\)
\(\{1 + \mathrm{i};\ -1 + \mathrm{i}\}\)
\(\{1 + \mathrm{i};\ 1 -\mathrm{i};\ -1 + \mathrm{i};\ -1 -\mathrm{i}\}\)

9000034305

Časť: 
B
Vyriešte danú rovnicu v množine komplexných čísel. \[ x^{4} + 16 = 0 \]
\(x_{1, 2} = \sqrt{2}(1\pm \mathrm{i}),\ x_{3, 4} = -\sqrt{2}(1\pm \mathrm{i})\)
\(x_{1, 2} = 1\pm \mathrm{i},\ x_{3, 4} = -1\pm \mathrm{i}\)
\(x_{1, 2} = 2(1\pm \mathrm{i}),\ x_{3, 4} = -2(1\pm \mathrm{i})\)
\(x_{1, 2} = \frac{\sqrt{2}} {2} (1\pm \mathrm{i}),\ x_{3, 4} = -\frac{\sqrt{2}} {2} (1\pm \mathrm{i})\)

9000034306

Časť: 
B
Vyriešte nasledujúcu rovnicu v množine komplexných čísel. \[ x^{6} - 64 = 0 \]
\(x_{1, 2} =\pm 2,\ x_{3, 4} = 1\pm \mathrm{i}\sqrt{3},\ x_{5, 6} = -1\pm \mathrm{i}\sqrt{3}\)
\(x_{1, 2} =\pm 2,\ x_{3, 4} = \frac{1} {2}\pm \mathrm{i}\frac{\sqrt{3}} {2} ,\ x_{5, 6} = -\frac{1} {2}\pm \mathrm{i}\frac{\sqrt{3}} {2} \)
\(x_{1, 2} =\pm 4,\ x_{3, 4} = 1\pm \mathrm{i}\sqrt{3},\ x_{5, 6} = -1\pm \mathrm{i}\sqrt{3}\)
\(x_{1, 2} =\pm 8,\ x_{3, 4} = 2\pm 2\mathrm{i}\sqrt{3},\ x_{5, 6} = -2\pm 2\mathrm{i}\sqrt{3}\)

9000034308

Časť: 
C
Dve riešenia rovnice \[ x^{3} + 1 + \mathrm{i} = 0 \] sú \[ \begin{aligned}x_{1}& = \root{6}\of{2}\left (\cos \frac{5} {12}\pi + \mathrm{i}\sin \frac{5} {12}\pi \right ),& \\x_{2}& = \root{6}\of{2}\left (\cos \frac{13} {12}\pi + \mathrm{i}\sin \frac{13} {12}\pi \right ). \\ \end{aligned} \] Nájdite tretie riešenie.
\(x_{3} = \root{6}\of{2}\left (\cos \frac{21} {12}\pi + \mathrm{i}\sin \frac{21} {12}\pi \right )\)
\(x_{3} = \root{6}\of{2}\left (\cos \frac{9} {12}\pi + \mathrm{i}\sin \frac{9} {12}\pi \right )\)
\(x_{3} = \root{6}\of{2}\left (\cos \frac{17} {12}\pi + \mathrm{i}\sin \frac{17} {12}\pi \right )\)
\(x_{3} = \root{6}\of{2}\left (\cos \frac{19} {12}\pi + \mathrm{i}\sin \frac{19} {12}\pi \right )\)