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Homework Help: Domain of 10/ln x

  1. May 21, 2006 #1
    I'm confused on this domain question

    10/ln x

    I really don't know where to start. Do I graph it and then go from there? :confused:
     
  2. jcsd
  3. May 21, 2006 #2
    what's the domain of ln(x)?
     
  4. May 21, 2006 #3
    0, infinity
     
  5. May 21, 2006 #4

    dav2008

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    Gold Member

    Basically I take it you are looking for the set of all x values for which the expression 10/ln(x) is defined, correct?

    So think to yourself, when is that expression not defined?

    (When you answered "0,infinity", did you mean (0,infinity)?)
     
  6. May 21, 2006 #5
    well if it equals -10, then I think that would make the numerator zero.

    But I think I need to look at the denominator. So it cannot be zero
     
    Last edited: May 21, 2006
  7. May 21, 2006 #6

    HallsofIvy

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    Science Advisor

    Yes, that's true. For what value of x is ln x= 0?

    Also, the domain of ln x is the open interval [itex](0, \infty)[/itex].
    Your "0, infinity" is ambiguous. 0 is not in the domain of ln x.
     
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