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nickersia

Medal to first who explains me this question :) Find the roots of the equation (comment).

  • 11 months ago
  • 11 months ago

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  1. nickersia
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    \[x ^{3}-x ^{2}-7x+3\]

    • 11 months ago
  2. shelbygt520
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    k whats the question

    • 11 months ago
  3. shelbygt520
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    ok do you want it factorized or what?

    • 11 months ago
  4. nickersia
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    That's problem, I'm not quite sure what should I do :s

    • 11 months ago
  5. shelbygt520
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    x^3+x^2-7x-3 One of the roots is x(1) = -3 After applying Polynomial remainder theorem you will have a second order equation x^2 - 2x - 1 = 0 a = 1 ; b = -2 ; c = -1 x(2,3) = (-b)(+/-)SqRoot{b^2 - 4 . a . c}/(2 a)= x(2,3) = (2)(+/-)SqRoot{4 - 4 . 1 . (-1)}/(2 . 1)= x(2,3) = (2)(+/-)SqRoot{4 + 4}/(2)= x(2,3) = 2 (+/-) SqRoot { 8 } / 2 = x(2,3) = 1 (+/-) SqRoot { 2 } ---> x(2) = 1 + SqRoot { 2 } ---> x(3) = 1 - SqRoot { 2 }

    • 11 months ago
  6. shelbygt520
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    u should do that but instead of doing minus you do the addition this was a mere example but close enough so that you would know what to do

    • 11 months ago
  7. nickersia
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    I understand second part perfectly that's not problem :) can you just explain how did you get -3 as one of the roots? I'm bit confused

    • 11 months ago
  8. shelbygt520
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    I just replaced +3 with -3 in this example

    • 11 months ago
  9. shelbygt520
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    so in your case the root would be +3

    • 11 months ago
  10. nickersia
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    Why is that?

    • 11 months ago
  11. shelbygt520
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    capish? :)

    • 11 months ago
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