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Math Help - Can this be solved??

  1. #1
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    Can this be solved??

    x^(2)+y^(2)=9

    I can't get pass y=sqrt(-x^2+9)
    The system I am submitting answers to says that there is a positive and a negative square root, and that the answers must be numbers. I have to find two solutions to both x and y.
    Could someone just point me in the right direction as to steps to solve this?
    I have a test Teus and I am so afraid I will flunk, help
    !
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  2. #2
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    Take a look at here
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  3. #3
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    Being that I am given no coordinates, that doesn't really help me. I guess the answer is an equation, but I do not do well with a ton of meaningless variables :/
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  4. #4
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    Must I find a center first?
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  5. #5
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    there is no "solving" here ... the equation x^2 + y^2 = 9 is a circle of radius 3 centered at the origin.
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  6. #6
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    oh, answers were -3 and 3 for both x and y
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  7. #7
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    Quote Originally Posted by md56 View Post
    oh, answers were -3 and 3 for both x and y
    ... that is only one of an infinite number of solutions.
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  8. #8
    Senior Member MacstersUndead's Avatar
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    To reinforce skeeter's point, consider polar coordinates, where x^2 + y^2 = r^2

    then r^2 = 9 => r = 3

    So any (x,y) Cartesian coordinate that is 3 units away from the origin is a solution.
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