MHB Principal value of complex number

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The discussion focuses on finding the principal value of the sixth root of the complex number \((\sqrt{3}+i)\). The principal sixth root is identified as \(\eta = \sqrt[6]{2}\exp\left(\frac{\pi}{36}\right)\), with other roots expressed as \(\eta \cdot \zeta^k\) for \(k=0,1,\ldots,5\), where \(\zeta = \exp\left(\frac{\pi}{3}\right)\). The principal value refers specifically to the root corresponding to \(k=0\). The conversation emphasizes the importance of understanding the distribution of roots around a circle in the complex plane. Ultimately, the principal value of the complex number itself is clarified through this analysis.
Suvadip
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Find all the values of $$(\sqrt{3}+i)^{1/6}$$. What is its principle value?I have doubt about the second part. We have heard about the principal value of the amplitude of a complex number. But here the principal value of the complex number itself is asked for. Please help
 
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Re: principal value of complex number

suvadip said:
Find all the values of $$(\sqrt{3}+i)^{1/6}$$. What is its principle value?

$$\eta = \sqrt[6]{2}\exp \left( {\frac{\pi }{{36}}} \right)$$ is one sixth root of $$\sqrt{3}+i$$.

If $$\zeta =\exp \left( {\frac{\pi }{{3}}} \right)$$ then $$\eta\cdot\zeta^k,~k=0,1,\cdots 5$$ are all six.

I have seen $$\eta$$ (i.e. $$k=0$$) called the principal root.
 
suvadip said:
Find all the values of $$(\sqrt{3}+i)^{1/6}$$. What is its principle value?I have doubt about the second part. We have heard about the principal value of the amplitude of a complex number. But here the principal value of the complex number itself is asked for. Please help

It helps if you remember that there are always two square roots, three cube roots, four fourth roots, etc, and they are all evenly spaced around a circle. So in this case, if you can evaluate one value, the rest will all have the same magnitude and be separated by an angle of [math] \displaystyle \frac{2\pi}{6} = \frac{\pi}{3} [/math].
 
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Obviously, there is something elementary I am missing here. To form the transpose of a matrix, one exchanges rows and columns, so the transpose of a scalar, considered as (or isomorphic to) a one-entry matrix, should stay the same, including if the scalar is a complex number. On the other hand, in the isomorphism between the complex plane and the real plane, a complex number a+bi corresponds to a matrix in the real plane; taking the transpose we get which then corresponds to a-bi...

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