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Math Help - Simple square rooting confusion

  1. #1
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    Question Simple square rooting confusion

    Is y^2 = 4 - x^2 the same as:


    y= 2 - x

    OR

    y= (4 - x^2)/y

    Thank you!
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  2. #2
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    y^2=4-x^2
    y=(4-x^2)^0.5 i suppose that it is equal to you second equation also.
    you must consider the right hand side of you equation in brakets when taking roots/squares. hope that helps
    (you must take the posotive and negative of (4-x^2)^0.5)
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  3. #3
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    Quote Originally Posted by RB89 View Post
    Is y^2 = 4 - x^2 the same as:


    y= 2 - x

    OR

    y= (4 - x^2)/y

    Thank you!
    Hi RB89,

    If you're wanting to solve for y, you will need to take the square root of both sides of the equation.

    y^2=4-x^2

    y=\sqrt{4-x^2}

    And that's about it.

    Now, if you had something like: y^2=4x^2, you could get to y=2x because the right side of the equation was a perfect square. That wasn't the case in your example.
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  4. #4
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    Quote Originally Posted by RB89 View Post
    Is y^2 = 4 - x^2 the same as:


    y= 2 - x

    OR

    y= (4 - x^2)/y

    Thank you!

    y^2=4-x^2 is NOT the same as y=2-x

    but it is the same as y=\frac{4-x^2}{y} , when you work it out , you should see that they are the same .
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