How to Calculate the Complex Roots of x^5 = 10?

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Homework Help Overview

The discussion revolves around finding the complex roots of the equation x5 = 10, with a focus on understanding the methods applicable for calculating these roots.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the need to show effort in solving the problem and mention the known real root. There are suggestions to use polar form and properties of complex numbers to find the complex roots. Questions arise about the appropriate methods and tools, such as Newton's method and Argand diagrams.

Discussion Status

The discussion is active, with participants exploring various methods and questioning the best approach to find the complex roots. Some guidance has been offered regarding the use of polar representation and the properties of complex numbers, but no consensus has been reached on a specific method.

Contextual Notes

There is an emphasis on showing work and understanding the underlying concepts rather than simply applying methods. The original poster expresses uncertainty about which method to use for finding the complex roots.

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Homework Statement
Given x^5=10, find the five roots and plot them on an Argand diagram.
Relevant Equations
Newton's method.
Mentor note: Member reminded that some effort must be shown.
Real root is 1.858.
Just don't know which method to use to find the 4 complex roots
 
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[tex]x^5=10[/tex]
[tex](\frac{x}{\sqrt[5]{10}})^5=z^5=1[/tex]

So get solutions of ##z^5=1## and multiply them with ##\sqrt[5]{10}##.
 
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Newton's method will only find the real solutions. With complex numbers, you should consider the properties of complex numbers to get the other, complex solutions. Even for the real solution, they probably don't want you to use Newton's method, but rather just leave that solution as ##10^{1/5}##.
For the complex solutions, do you know about the representation of a complex number in its polar form (##re^{i\theta}##)? If so, consider 10 in its polar form: ##10e^{i0} = 10e^{i2\pi}= 10e^{i4\pi}= 10e^{i6\pi}= 10e^{i8\pi}= 10e^{i10\pi}##. Now take the fifth root of the individual factors, 10 and ##e^{i2n\pi}##
 
mardybum9182 said:
Just don't know which method to use to find the 4 complex roots

Do you know what an Argand diagram is?
 

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