SOLUTION: Three roots of the polynomial equation x^4 - 4x^3 - 2x^2 + 12x + 9 = 0 are 3, -1 and -1. Explain why the fourth root must be a real number. Find the fourth root.

Question 947912: Three roots of the polynomial equation x^4 - 4x^3 - 2x^2 + 12x + 9 = 0 are 3, -1 and -1. Explain why the fourth root must be a real number. Find the fourth root.
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Because complex roots only occur, in polynomial with integer coefficients, as complex conjugate pairs so there would be two of them.

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