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
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) (Show Source):
You have to know 2 things:
1. How to change from a+bi form to trig form r(cosq + i sinq)
use tanq = and r =
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+2i form to trig form r(cosq + i·sinq)
use tanq = =
therefore q = 60°
and r = = = = = 4
So 2 + 2i = 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