Question 119630
find all zeros
1.f(x)= x^4+2x^3-11x^2+8x-60
I graphed it and found Real zeroes at x=-5 and x=3
Using synthetic division you can find the quadratic factor:
-5)....1....2....-11....8....-60
........1....-3.....4....-12...|..0
3).......1......0.....4.....0

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Remainder: 0
Quotient : x^2+4
Factors of the Quotient: (x-2i)(x+2i)
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Zeroes: -5,3,2i,-2i
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2.f(x)= x^4-8x^3-8x^22x^2-8x-39

Comment: There is some confusion in your posting
for #2.
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Cheers,
Stan H.