Question 894839
Given f(x)=-x^3+7x^2-9x-5 & that x=5 is a root, find the other roots. (Find the depressed equation, then use the quadratic formula). Simplify your answer as much as possible, but do not approximate with decimals. -----
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Using synthetic division::
5)....-1....7....-9....-5
......-1....2.....1...|..0
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Quotient:: -x^2 + 2x + 1
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Using the quadratic formula::
x = [-2 +- sqrt(4 - 4*-1*1)]/-2
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x = [-2 +- sqrt(8)]/(-2)
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x = [-2+-2sqrt(2)]/(-2)
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x = 1 +- sqrt(2)
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Cheers,
Stan H.
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