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Math Help - Find Range and Domain!?!?!?!?

  1. #1
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    Find Range and Domain!?!?!?!?

    ok i dont actually know how to find the range and domain of a function so could anyone please show me how, and also this is my question that needs answering please.

    f:x = 2x + ln2
    g:x = e^(2x)

    gf:x = 4e^(4x), (x E R)

    the question asks to find the range of gf.


    Part (c) is write down the range and domain of: ln(4-2x)
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  2. #2
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    Quote Originally Posted by Stylis10 View Post
    ok i dont actually know how to find the range and domain of a function so could anyone please show me how, and also this is my question that needs answering please.

    f:x = 2x + ln2
    g:x = e^(2x)

    gf:x = 4e^(4x), (x E R)

    the question asks to find the range of gf.
    The range of 4e^{4x} is (0,\infty). The range is essentially the range of e^t and we know that e^t is always positive.


    Part (c) is write down the range and domain of: ln(4-2x)
    \ln y is defined only when y > 0, using this we can say the domain is 4 - 2x > 0 \Rightarrow x < 2. Thus the range is \mathbb{R}.
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  3. #3
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    Quote Originally Posted by Isomorphism View Post
    The range of 4e^{4x} is (0,\infty). The range is essentially the range of e^t and we know that e^t is always positive.




    \ln y is defined only when y > 0, using this we can say the domain is 4 - 2x > 0 \Rightarrow x < 2. Thus the range is \mathbb{R}.

    thans that helped alot
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