Solving a Complex Polynomial Equation

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Homework Help Overview

The discussion revolves around solving the complex polynomial equation (z^4) + 1 = 0, focusing on the roots of the equation in the context of complex numbers.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants explore the factorization of the polynomial and consider the implications of setting z^2 equal to i and -i. There is mention of using polar form to assist in finding the roots.

Discussion Status

Some participants have offered hints and suggestions for approaching the problem, including the use of polar coordinates. The discussion appears to be progressing with participants expressing gratitude for the guidance provided.

Contextual Notes

There is an emphasis on the need to solve for z^2 = i and z^2 = -i, indicating that participants are working within the constraints of complex number solutions.

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Homework Statement



Happy New Year, everybody!

Problem: Solve (z^4)+1 = 0


Homework Equations





The Attempt at a Solution



Attempt: (z^4)+1 = 0
((z^2)+i)*((z^2)-i) = 0

Could anyone help me to complete this question please?

Many Thanks!
 
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HINT: Let [itex]z = e^{i\theta}[/itex]
 
wam_mi said:

Homework Statement



Happy New Year, everybody!

Problem: Solve (z^4)+1 = 0


Homework Equations





The Attempt at a Solution



Attempt: (z^4)+1 = 0
((z^2)+i)*((z^2)-i) = 0

Could anyone help me to complete this question please?

Many Thanks!
So you know that z^2+ i= 0 and z^2- i= 0. Now you need to solve z^2= i and z^2= -i.

You can, as Hootenanny suggested, write i and -i in "polar form" and use the fact that
[tex]\left(re^{i\theta}\right)^{1/2}= r^{1/2} e^{i\theta/2}[/tex]
 
HallsofIvy said:
So you know that z^2+ i= 0 and z^2- i= 0. Now you need to solve z^2= i and z^2= -i.

You can, as Hootenanny suggested, write i and -i in "polar form" and use the fact that
[tex]\left(re^{i\theta}\right)^{1/2}= r^{1/2} e^{i\theta/2}[/tex]



Thanks a lot for your help HallsofIvy. I think I can do it now, thank you!
 
HallsofIvy said:
So you know that z^2+ i= 0 and z^2- i= 0. Now you need to solve z^2= i and z^2= -i.

You can, as Hootenanny suggested, write i and -i in "polar form" and use the fact that
[tex]\left(re^{i\theta}\right)^{1/2}= r^{1/2} e^{i\theta/2}[/tex]


Thanks for the hint!
 

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