Use DeMoivre's Theorem to write the complex number in standard form.


(√2(cos(20°) + isin(20°))^6


A4√3 + 4i

B- 4 + 4√3 i

C4 + 4√3 i

D- 4√3 + 4i

Verified Answer :

caylus

Hello,

Answer B

(√2(cos(20°) + isin(20°))^6 =8(cos 120°+isin120°)
=8
(-1/2+i√3/2)
=4(-1+i√3)



Answer:

Option B is correct

\(-4+ 4\sqrt{3}i\)

Step-by-step explanation:

Given the complex number:  

\((\sqrt{2}(\cos(20^{\circ})+i\sin(20^{\circ})))^6\)

Using D-Moivre's theorem:

if p is the rational; number:

\((\cos \theta +i\sin \theta)^p = \cos p\theta +i\sin\theta\)

then;

Using D-Moivre's theorem:

\((\sqrt{2})^6(\cos(6 \cdot 20^{\circ})+i\sin(6 \cdot 20^{\circ}))\)

\(8((\cos(120^{\circ})+i\sin(120^{\circ}))\)

\(8(-\frac{1}{2}+i \frac{\sqrt{3}}{2}) = -4+ 4\sqrt{3}i\)

Therefore, the given complex in the standard form is \(-4+ 4\sqrt{3}i\)