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Homework Help: Please Help with Domain

  1. Nov 19, 2007 #1
    Please Help with Domain......

    1. The problem statement, all variables and given/known data

    For f(x) Determine Domain, Vertical Asymptote and x and y intercepts. then State and graph the effect of the modifications and sketch the graph of f(x)
    Given f(x) = - log3(x – 1) + 2

    For g(x) determine domain, Horizontal asymptote and x and y intercepts. then state and graph the effect of the modifications and sketch the graph of g(x)
    Given g(x) = 3 - x + 1 - 9
  2. jcsd
  3. Nov 19, 2007 #2
    Lets begin with the first problem. To find the domain, consider when the log of something not exist. Let me know if this is what's confusing you.
  4. Nov 19, 2007 #3
    yes that is a confusing part, I know how to find the Domain, but not when involving log
  5. Nov 19, 2007 #4
    Ok, so lets say I have y = log( 2 - x) - 1, and I want to find the domain of the function. You should know that the log of zero, or any negative quantity does not exist. So I would set the function inside of the log equal to zero:

    2 - x = 0 ---> x = 2.

    Now I know that the function exists as long as x is greater than 2. It does not exist when x is two or less. This is our domain. Does that make sense?
  6. Nov 19, 2007 #5
    yes thank you.
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