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anonymous

  • one year ago

Between what two successive integers does a real zero of P(x) = x3 –2x –5 lie? what are successive integers?

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  1. asnaseer
    • one year ago
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    successive integers are integers that follow each other. e.g. 4 and 5 are successive integers, 18 and 19 are successive integers, etc

  2. anonymous
    • one year ago
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    you can find the zeros of \(P(x)\), and find the integers from that value... for example if you find the real zero to be \(x=1.32\) then you know it lies between \(1\) and \(2\) ---( This is not the solution, i just made up an example ! )

  3. ParthKohli
    • one year ago
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    Hey, let \(f(x) = x^3 - 2x - 5\). Notice that \(f(2) = -1\) and \(f(3) = 16\). Therefore a root lies in the interval (2,3).

  4. anonymous
    • one year ago
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    @Greg_D thanks. so all i have to do is find the zero and did whatever it's between is the answer?

  5. anonymous
    • one year ago
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    yes! remmeber your answer must be integer numbers!

  6. anonymous
    • one year ago
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    oh ok. it is between 2 and 3 like parthkohli said. i also must use calculator. Thanks for the help!

  7. ParthKohli
    • one year ago
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    Here, I used the Intermediate Value Theorem. There's no real need for a calculator although you can graph the function.

  8. anonymous
    • one year ago
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    :) you are welcome! @ParthKohli showed a more efficient way to solve this, without finding the value of the zero !

  9. asnaseer
    • one year ago
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    you don't need to actually work out the roots of this equation first.

  10. asnaseer
    • one year ago
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    you need to try successive integers until you observe a sign change - Intermediate Value Theorem as @ParthKohli stated

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