SOLUTION: Find all the zeros of the polynomial x3 - 4x2 + 9x - 36

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Question 90357: Find all the zeros of the polynomial x3 - 4x2 + 9x - 36
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find all the zeros of the polynomial x^3 - 4x^2 + 9x - 36
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I graphed it to find a zero at x=4
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Then using synthetic division I get:
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4)....1....-4....9....-36
........1.....0....9....|..0
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Remainder is zero
Quotient is x^2+9
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Find the zeroes of the quotient:
x^2 + 9 = 0
(x-3i)(x+3i)=0
x=3i or x=-3i
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Now you have the three zeroes of the function.
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Cheers,
Stan H.