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Homework Help: Domain and range help

  1. Aug 2, 2016 #1
    1. The problem statement, all variables and given/known data
    Suppose f is a function with domain [-2,10] and range [5,10]. Find the domain and range of the following functions.
    (a) f(2x+4)

    (b) 2f(x)+4

    3. The attempt at a solution

    Would I just substitute the in the domain and range values to find the answer?
  2. jcsd
  3. Aug 2, 2016 #2


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    Don't ask. Do it: that counts as an attempt at solution. Ask when stuck...
    Or (in a friendlier manner :smile:) what do you get when you do as you propose ?
  4. Aug 2, 2016 #3
    [-2,10] if i sub this values into f(2x+4) i would get 0 and 24 does this mean that the domain would be (0,24)

    Would I just do the same for the range?
  5. Aug 2, 2016 #4


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    Staff: Mentor

    Do you know what is meant by domain and range? Can you define it?
    Hint: Is f(24) defined?
  6. Aug 2, 2016 #5
    the domain is pairs of x coordinates in order and the range is pairs of y coordinates in order
  7. Aug 2, 2016 #6


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    The domain of a function is the set of values which are allowed to be used as inputs to the function. The notation "[-2,10]" denotes a range of values from -2 up through 10, inclusive. It does not denote an ordered pair.
  8. Aug 2, 2016 #7


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    Remember that ##f(2x+4)=f\circ g## where ##g(x)=2x+4##, the composition requires that the range of ##g## is included in the domain of ##f## ...
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