Complex number polynomial, with no root given

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Homework Help Overview

The problem involves solving a cubic polynomial equation with complex coefficients, specifically z^3 + (-5+2i)z^2 + (11-5i)z -10+2i = 0, and identifying all solutions given that there is a real root.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the challenge of finding a real solution without a given root and explore the idea of assuming a real solution to test its validity. There is mention of separating real and imaginary parts to find mutual solutions.

Discussion Status

The discussion includes attempts to clarify the process of finding a real solution, with one participant indicating they found a method to derive the solution. However, there is also concern about the appropriateness of assuming a solution without verification.

Contextual Notes

Participants express the constraint of needing to adhere to homework guidelines, which may discourage assuming solutions without justification.

Jarfi
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Homework Statement



z^3 + (-5+2i)z^2 + (11-5i)z -10+2i =0 has a real root, find all the solutions to this equation.


The Attempt at a Solution



I have only solved imaginary number polynomials with a given root, but this has no given root, how do I find the real solution? that I can then use to factor it and find the rest of the solutions.
 
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If you have no other techniques available, you can always assume a real solution and see if it satisfies the equation.
 
SteamKing said:
If you have no other techniques available, you can always assume a real solution and see if it satisfies the equation.

Oh nevermind, I found out how you do it, you just define a as a real number, put it in and get a real and imaginary part, both real and imaginary part are suppost to be equal to zero, so their mutual solution is the available real solution, this gave me the answer of two.
 
SteamKing said:
If you have no other techniques available, you can always assume a real solution and see if it satisfies the equation.

I already knew the 2 was an answer but my teacher would frown upon me if I'd assume a solution.
 

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