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| Question 819497:  Write a third degree polynomial function y=P(x) with rational coefficients so that P(x)=0 has the given roots.
 1, 2-i
 3, 6+i
 3i, 7
 1, 5i
 3, -4i
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! Write a third degree polynomial function y=P(x) with rational coefficients so that P(x)=0 has the given roots. 1, 2-i and 2+i
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 P(x) = (x-1)(x-2+i)(x-2-i)
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 = (x-1)[(x-2)+i)(x-2)-i)]
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 = (x-1)[(x-2)^2+1]
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 = (x-1)(x^2-4x+5)
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 = x^3 - 5x^2 + 9x -5
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 Cheers,
 Stan H.
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 3, 6+i
 3i, 7
 1, 5i
 3, -4i
 
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