SOLUTION: Use Demoivre's Theorem to find the indicated power of the complex number (2+2squareroot3i)^6 not even sure how to start this help would be greatly appreciated

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Question 565116: Use Demoivre's Theorem to find the indicated power of the complex number
(2+2squareroot3i)^6
not even sure how to start this
help would be greatly appreciated

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
You have to know 2 things:

1. How to change from a+bi form to trig form r(cosq + i sinq)

use tanq = b%2Fa and r = sqrt%28a%5E2%2Bb%5E2%29

2.  How to raise a complex number in trig form using DeMoivre's
   formula:

[r(cosq + i sinq)]n = rn[cos(nq) + i·sin(nq)]


(2+2squareroot3i)^6


1. To change from 2+2sqrt%283%29i form to trig form r(cosq + i·sinq)

use tanq = %282sqrt%283%29%29%2F2 = sqrt%283%29
therefore q = 60°

and r = sqrt%282%5E2%2B%282sqrt%283%29%29%5E2%29 = sqrt%284%2B4%2A3%29 = sqrt%284%2B12%29 = sqrt%2816%29 = 4

So 2 + 2sqrt%283%29i = 4(cos60° + i·sin60°) 


2. To raise this complex number in trig form using DeMoivre's
   formula:

[4(cos60° + i·sin60°)]6 = 46[cos(6·60°) + i·sin(6·60)] =
4096(cos360° + i·sin360°) = 4096(cos0° + i·sin0°) = 
4096(1+i·0) = 4096(1+0) = 4096(1) = 4096.

answer: 4096.

Edwin