Principal value of complex number

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SUMMARY

The principal value of the complex number $$(\sqrt{3}+i)^{1/6}$$ is defined as $$\eta = \sqrt[6]{2}\exp \left( {\frac{\pi }{{36}}} \right)$$, which represents one of its sixth roots. The complete set of sixth roots can be expressed as $$\eta\cdot\zeta^k$$ for $$k=0,1,\cdots 5$$, where $$\zeta =\exp \left( {\frac{\pi }{{3}}} \right)$$. The principal root is identified as the value for $$k=0$$. Understanding the distribution of roots around a circle is crucial for evaluating these complex numbers.

PREREQUISITES
  • Complex number theory
  • Understanding of exponential functions in complex analysis
  • Knowledge of roots of unity
  • Familiarity with polar coordinates in the complex plane
NEXT STEPS
  • Study the properties of complex roots and their geometric interpretations
  • Learn about the Argand plane and how to represent complex numbers graphically
  • Explore the concept of principal values in complex analysis
  • Investigate the application of De Moivre's Theorem in finding roots of complex numbers
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Mathematicians, students of complex analysis, and anyone interested in understanding the properties and applications of complex numbers and their roots.

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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