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Math Help - simple question ... just can't figure it out

  1. #1
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    simple question ... just can't figure it out

    Solove for y:

    y^(2/3) = 2 - y^4

    SHOW THE STEPS PLZ
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  2. #2
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    Why do you believe it can be solved?

    What methods have you for your attempt?

    What have you tried?

    Just looking at it, I think I'd try y = 1 and y = -1.
    Last edited by mr fantastic; April 11th 2009 at 04:02 PM. Reason: Replaced x with y
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  3. #3
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    Quote Originally Posted by lidstrompl View Post
    Solove for y:

    y^(2/3) = 2 - y^4
    Let x = y^(1/3), so y^(2/3) = x^2 and y^4 = y^(12/3) = x^12.

    Substituting, you should get x = 2 - x^12, so you are trying to find the solutions of x^12 + x^2 - 2 = 0, which are the x-intercepts of f = x^12 + x^2 - 2.

    Plug x^12 + x^2 - 2 into your graphing calculator to "see" where the two real-values zeroes are. Divide out the two rational zeros (which duplicate the two rational zeroes of the original equation).

    You should be left with an equation in x^10 which has no real zeroes.
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  4. #4
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    Quote Originally Posted by TKHunny View Post
    Why do you believe it can be solved?

    What methods have you for your attempt?

    What have you tried?

    Just looking at it, I think I'd try x = 1 and x = -1.

    ye, just noticed that as well. Just didn't want to get messy with unnecessary algebra. 1 and -1 in the solution is actually all i need for my problem. Thanks.
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