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  1. #1
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    functions problem

    HERE THE ACTIVITY

    Last edited by juanpablo; April 7th 2010 at 01:51 PM. Reason: now in image the activity
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  2. #2
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    Quote Originally Posted by juanpablo View Post
    plotting the filing of

    f (X) = + √x-1 and answer:



    [ITEM C] Look at the domain of

    f (X) = + √x-1 and find one or more relationships with the intervals of positivity, negativity and invalidity of the previous table. Properly express the conclusion.

    a) When is a function: g (X) = x-1?. Write the answer algebraically.


    point 2 )
    What values of x, f(x)=√x-1 is a function?. Analytically justify and explain why it is the function in the range found.


    note
    in the point 2
    when say f(x)=√x-1 i want say "cube root"


    Integrative Activity:

    Expressed in general terms the conclusions found in part c) (see above)
    I'd like to help, but I don't think you copied the questions down well enough for people to understand what needs to be found.

    For example, there's a reference to a table, but you didn't copy the table. Also, it's not entirely clear whether f(x)=(x-1)^(1/2) or f(x)=x^(1/2)-1. And then in point 2 you redefine f(x) using cube roots, but normally a textbook or worksheet would use a different letter to avoid confusion, since we already used f(x) to mean something else.

    Also the question "when will g(x)=x-1 be a function" doesn't seem to make much sense, since that is always a function, for all real x.

    Would it be possible to take a picture of the problem and upload using, say, tinypic.com?
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  3. #3
    MHF Contributor undefined's Avatar
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    Quote Originally Posted by juanpablo View Post
    HERE THE ACTIVITY

    OK, I see the worksheet itself is a little hard to understand the way it's written, but I'll try to answer:

    a) g(x)=x-1 is a function for all real x. This could be written in several different ways, including x\in\mathbb{R} and x\in(-\infty, \infty).

    b)

    Greater than zero: x\in(1, \infty)

    Less than zero: x\in(-\infty, 1)

    Equal to zero: x=1

    c) The domain of f(x) is x\in[1, \infty). This corresponds to g(x)\geq0.

    Follow up question: f(x)=\sqrt[3]{x-1} is a function for x\in\mathbb{R} because all real numbers have exactly one real cube root. Thus as long as x-1 is a real number, f(x) will associate it with a unique value. The range is also all real numbers.

    Integrative Activity: For a function f(x)=\sqrt{h(x)}, the domain of f(x) is described by h(x)\geq0.
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  4. #4
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    Quote Originally Posted by undefined View Post
    OK, I see the worksheet itself is a little hard to understand the way it's written, but I'll try to answer:

    a) g(x)=x-1 is a function for all real x. This could be written in several different ways, including x\in\mathbb{R} and x\in(-\infty, \infty).

    b)

    Greater than zero: x\in(1, \infty)

    Less than zero: x\in(-\infty, 1)

    Equal to zero: x=1

    c) The domain of f(x) is x\in[1, \infty). This corresponds to g(x)\geq0.

    Follow up question: f(x)=\sqrt[3]{x-1} is a function for x\in\mathbb{R} because all real numbers have exactly one real cube root. Thus as long as x-1 is a real number, f(x) will associate it with a unique value. The range is also all real numbers.

    Integrative Activity: For a function f(x)=\sqrt{h(x)}, the domain of f(x) is described by h(x)\geq0.


    thanks you friend , you help was help to me so much
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