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Help with functions please!

  1. Sep 8, 2008 #1
    Let f be the set of all ordered pairs (x,y) such that x and y belong to R and y = x2. Is this a function?
    The same question, for f be the set of all ordered pairs (x,y) such that x and y belong to R and x=y2. Is this a Function?



    I think for the first one y=x2 it is a function because there is a unique y value for every x value that is given.

    For the second one, I think that x=y2 is not a function because there is not a unique y value for every x. Because if x=2 then y can = -2 and 2.

    Is this right?

    Thanks for the help!
     
  2. jcsd
  3. Sep 8, 2008 #2
    You are correct.

    Also, the graph of y = [tex]x^{2}[/tex] passes the vertical line test.

    The 2nd function's graph doesn't.
     
  4. Sep 8, 2008 #3
    thank you!!
     
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