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

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In summary, the conversation discusses finding the roots of a complex equation and suggests using the properties of complex numbers and an Argand diagram to find the complex solutions. The member is reminded to show effort in finding the solutions.
  • #1
mardybum9182
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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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  • #2
[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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  • #3
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}##
 
  • #4
mardybum9182 said:
Just don't know which method to use to find the 4 complex roots

Do you know what an Argand diagram is?
 

1. What does "finding the roots" mean in this context?

Finding the roots of an equation means determining the values of the variable (in this case, x) that make the equation true.

2. How many roots does this equation have?

This equation has five roots, as indicated by the exponent of 5 in the equation.

3. Is there a specific method for finding the roots of this equation?

Yes, there are several methods for finding the roots of an equation, including factoring, using the quadratic formula, or using numerical methods such as Newton's method.

4. Can this equation have complex roots?

Yes, this equation can have complex roots, as the exponent of 5 indicates that it is a polynomial of degree 5, which can have both real and complex roots.

5. How do I check if my solution is correct?

You can check your solution by substituting the value of x into the original equation and verifying that it satisfies the equation. You can also use a graphing calculator to plot the equation and see where it intersects the x-axis, which will be the roots.

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