Question 614524: I have been requested to factorize the following equation for a calculus calculation I am struggling with.
Y = x^3 - 3x^2 - 9x - 5
I begun in the following manner.
0=x(x^2-3x-9)-5
5=x(x^2-3x-9)....
....From that point I failed to understand my calculation.
Your assistance will be highly appreciated.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Y = x^3 - 3x^2 - 9x - 5
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It looks like f(-1) = 0
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Use synthetic division to see.
-1)....1....-3....-9....-5
........1.....-4...-5...|..0
Quotient: x^2 -4x-5
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Factor the quotient:
(x-5)(x+1)
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Final factored form: (x+1)^2(x-5)
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Note: The fastest way to find one or more
Real Number zeroes is to graph the function
with a graphing calculator. Hopefully you
have a graphing calculator, if you are studying
calculus.
Cheers,
Stan H.
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