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Homework Help: What are the domain and range of this relation

  1. Dec 13, 2011 #1
    in interval notation?



    [itex]y^2(x^2 - 1) = x^4[/itex]





    (This is my own problem.)
     
  2. jcsd
  3. Dec 13, 2011 #2

    berkeman

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    Staff: Mentor

    Do you know the definition of Domain and Range of a function? Can you tell us what you think they are?

    Then, is there anything that would inherently limit the domain of the function?

    EDIT -- BTW, you haven't really defined a function yet. Domain and Range generally apply to a function...
     
  4. Dec 13, 2011 #3

    berkeman

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    Staff: Mentor

    If you put the relation into the form y = f(x), then you can talk about the Domain and Range of that function...
     
  5. Dec 13, 2011 #4

    Mark44

    Staff: Mentor

    Your equation is equivalent to
    [tex]y^2 = \frac{x^4}{x^2 - 1}[/tex]
    From this, you can solve for y.
     
  6. Dec 13, 2011 #5

    I am not trying to define a function. I know this is a relation
    that is not a function.

    And relations can have domains and ranges, as this one does.

    In this problem I am challenging others with, I expect others to know
    what the domain and range mean, but those aren't questions for me
    in this particular problem.



    One of many sources:

    http://www.purplemath.com/modules/fcns2.htm

    This relation can't be put into into a form y = f(x), because it isn't
    a function to begin with.
     
  7. Dec 13, 2011 #6
    No, I am testing (read: challenging) users' knowledge
    of domain and range to figure them out of this relation,
    whether in my form or the equivalent form given by
    Mark44.

    I will be on at least a 90-minute break before returning
    to this thread.
     
  8. Dec 13, 2011 #7

    Mark44

    Staff: Mentor

    It would have been helpful to include that information in your first post.

    And that brings up a question: Since this isn't a question for you, why did you post it?
     
  9. Dec 13, 2011 #8
    Since this is just testing of our knowledge, this means that this isn't a valid homework problem. So the thread can be locked.
     
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