Question 983908
 Find all zeros of the polynomial functions. Show the process. 
x^4 - 2x^3 + 6x^2 - 18x -27
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Graph to see the zeroes::
{{{graph(400,400,-10,10,-10,10,x^4-2x^3+6x^2-18x-27)}}}
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Use the zero at x = 3
3)....1....-2....6....-18....-27
......1.....1....9....9....|..0

Use the zero at x = -1
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-1)....1....1....9....9
.......1....0....9...|..0

Factor:: x^2 + 9 = 0
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Imaginary zeroes:: x = 3i or x = -3i
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Ans: Zeroes at x = 3 OR x = -1 OR x = 3i OR x = -3i

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Cheers,
Stan H.
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