Question 770788: find a rational zero of the polynomial function and use it to find all the zeros of the function.
f(x)=x^3+2x^2-5x-6
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! find a rational zero of the polynomial function and use it to find all the zeros of the function.
f(x)=x^3+2x^2-5x-6
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Since f(-1) = 0, x = -1 is a root.
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Use x = -1 to find other roots:
-1)....1....2....-5....-6
.......1....1....-6...|..0
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Quotient: x^2 +x -6
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Factor:
(x+3)(x-2) = 0
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x =-3 or x = 2
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Rational roots: -1,-3,2
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Cheers,
Stan H.
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