Kompleks Daraja 079170
1. Muammo: Kompleks sonni darajaga ko'tarish formulasi va misollar bilan tushuntirish.
2. Kompleks sonni darajaga ko'tarish formulasi De Moivre teoremasiga asoslanadi:
$$\left( r(\cos \theta + i \sin \theta) \right)^n = r^n \left( \cos(n\theta) + i \sin(n\theta) \right)$$
Bu yerda $r$ - kompleks sonning modulidir, $\theta$ - argumenti, $n$ - butun son.
3. Misol: $z = 1 + i$
Avvalo, $r = |z| = \sqrt{1^2 + 1^2} = \sqrt{2}$
Argument $\theta = \arctan\left( \frac{1}{1} \right) = \frac{\pi}{4}$
4. $z^3 = r^3 \left( \cos 3\theta + i \sin 3\theta \right) = (\sqrt{2})^3 \left( \cos \frac{3\pi}{4} + i \sin \frac{3\pi}{4} \right)$
5. Hisoblaymiz:
$$(\sqrt{2})^3 = (2^{1/2})^3 = 2^{3/2} = 2 \sqrt{2}$$
$\cos \frac{3\pi}{4} = -\frac{\sqrt{2}}{2}$, $\sin \frac{3\pi}{4} = \frac{\sqrt{2}}{2}$
6. Shunday qilib,
$$z^3 = 2 \sqrt{2} \left( -\frac{\sqrt{2}}{2} + i \frac{\sqrt{2}}{2} \right) = 2 \sqrt{2} \left( -\frac{\sqrt{2}}{2} \right) + 2 \sqrt{2} \left( i \frac{\sqrt{2}}{2} \right)$$
$$= 2 \sqrt{2} \cdot -\frac{\sqrt{2}}{2} + i \cdot 2 \sqrt{2} \cdot \frac{\sqrt{2}}{2} = -2 + 2i$$
7. Natija: $z^3 = -2 + 2i$
Bu usul bilan har qanday kompleks sonni darajaga ko'tarish mumkin.