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OpenStudy (candy13106):
0.5 - 0.866025404 i
OpenStudy (anonymous):
can you tell me how you did it please?
OpenStudy (freckles):
I think you are looking for something else
OpenStudy (freckles):
\[\text{ Let } x=\frac{1}{2}-\frac{\sqrt{3}}{2}i \]
first let's write this number in trigonometric form
OpenStudy (freckles):
do you know how to do that
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OpenStudy (freckles):
hint the form that I seek is
\[x=\cos(\theta)+\sin(\theta) i\]
OpenStudy (anonymous):
can you give me a sec
OpenStudy (freckles):
k
OpenStudy (anonymous):
i am trying to do it on paper sorry DX
OpenStudy (freckles):
you can use the unit circle
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OpenStudy (freckles):
when is cosine 1/2 and sine -sqrt(3)/2
OpenStudy (anonymous):
On my test in school, my teacher doesn't allow us to use the unit circle so i am trying to remember it by memories
OpenStudy (anonymous):
so would it be cos(5pi/3)+isin(5pi/3)?
OpenStudy (freckles):
coolness
OpenStudy (freckles):
\[x=\cos( \frac{5\pi}{3}+2n \pi)+i \sin(\frac{5\pi}{3}+2n \pi) \\ x=e^{i (\frac{5 \pi}{3} +2 n \pi)} \\ x^\frac{1}{4}=e^{\frac{i}{4}( \frac{5\pi}{3}+2 n \pi)} \\ \]
you want 4 numbers
so n=0 will give you one
n=1 gives you another
n=2 gives you your 3rd one
and finally n=3 gives you your last 4th root