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Math Help - Is this question flawed?

  1. #1
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    Is this question flawed?

    I am given the equation of a curve: y=x^3 - 5x - (2/x) where x is not equal to 0.

    I am told that the points A and B which are (1,-2) and (-1,2) lie on it.

    However, when one substitutes 1 and -1 into the equation one gets: -6 and 6 respectively.

    I am pretty sure i am not going mad and this is a misprint (it is supposed to be a past exam question from what i gather.)

    Am i right?

    Thanks
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  2. #2
    Eater of Worlds
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    There is a typo in the equation.

    If it were x^{3}-5x+\frac{2}{x}, then it'll work OK.
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  3. #3
    Grand Panjandrum
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    Quote Originally Posted by StaryNight View Post
    I am given the equation of a curve: y=x^3 - 5x - (2/x) where x is not equal to 0.

    I am told that the points A and B which are (1,-2) and (-1,2) lie on it.

    However, when one substitutes 1 and -1 into the equation one gets: -6 and 6 respectively.

    I am pretty sure i am not going mad and this is a misprint (it is supposed to be a past exam question from what i gather.)

    Am i right?

    Thanks
    Prabably y=x^3 - 5x + (2/x) was intended.

    CB
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