SOLUTION: f(x) = x^3 + 2x^2 – 5x – 10. Find a bound for the real zeros of f and graph f (x) and find all real zeros of the function. Approximate all irrational zeros rounded to two dec

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Question 383381: f(x) = x^3 + 2x^2 – 5x – 10.
Find a bound for the real zeros of f and graph f (x) and find all real zeros of the function. Approximate all irrational zeros rounded to two decimal places.
Answer by Fombitz(32388)   (Show Source): You can put this solution on YOUR website!

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The real zeros lies between (,).
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Looks like is a zero.
Verify using the equation,



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Since is a zero, then is a factor.
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Use polynomial long division to find the other quadratic factor, 

        x^2 - 5
       __________________________
x + 2 | x^3 + 2x^2 - 5x - 10
     - (x^3 + 2x^2)
       ---------------------
                   - 5x - 10
                - (- 5x - 10)
                -------------
                           0

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For the quadratic equation,



You can approximate those zeros with a calculator to the desired number of decimal places.

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