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Math Help - graphing degree 3 eqn, help with roots.

  1. #1
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    graphing degree 3 eqn, help with roots.

    Hi,

    I am studying on my own. The textbook contains a graph of the following f(x)=-x^3+x+1.
    I have successfully graphed the function, and note that there actually is one real root at about 1.3 or so.

    Is there any way of finding this root algebraically. Perhaps even a link to a web site somewhere detailing how this root might be found? It probably has other complex roots too? I am really interrested in the real one.

    Factoring doesn't get me far -x(x^2-1)=-1

    Any direction would be much appreciated.

    Thanks
    Craig.
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  2. #2
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    Quote Originally Posted by craigmain View Post
    Hi,

    I am studying on my own. The textbook contains a graph of the following f(x)=-x^3+x+1.
    I have successfully graphed the function, and note that there actually is one real root at about 1.3 or so.

    Is there any way of finding this root algebraically. Perhaps even a link to a web site somewhere detailing how this root might be found? It probably has other complex roots too? I am really interrested in the real one.

    Factoring doesn't get me far -x(x^2-1)=-1

    Any direction would be much appreciated.

    Thanks
    Craig.
    The "Cubic Formula"
    Follow Math Help Forum on Facebook and Google+

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