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Thread: domain, function and subset help *please help!!*

  1. December 5th 2006, 02:49 PM #1
    fatcow2000
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    domain, function and subset help *please help!!*

    hey guys, im new here, i need some help on a take home test (go figure)...

    the questions are easy, but our teacher never helped us with them and doesnt explain very well, please help me with these questions:

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  2. December 5th 2006, 03:04 PM #2
    OReilly
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    Quote Originally Posted by fatcow2000 View Post
    hey guys, im new here, i need some help on a take home test (go figure)...

    the questions are easy, but our teacher never helped us with them and doesnt explain very well, please help me with these questions:

    Domain of the function f(x) = \sqrt x is x\ge0



    Substitute x for -2:
    \begin{array}{l}<br /> f(x) = x^2 - 2x + 3 \\ <br /> f( - 2) = ( - 2)^2 - 2 \cdot ( - 2) + 3 \\ <br /> f( - 2) = 4 + 4 + 3 \\ <br /> f( - 2) = 11 \\ <br /> \end{array}<br />

    First you find g(2):
    \begin{array}{l}<br /> g(2) = 2^2 - 1 \\ <br /> g(2) = 3 \\ <br /> \end{array}<br />

    Now find f(3):
    \begin{array}{l}<br /> f(3) = 2 \cdot 3 + 1 \\ <br /> f(3) = 7 \\ <br /> \end{array}<br />

    So: f(g(2)) = 7


    Set of five elements can have: 5+10+10+5+1=31 subsets and empty set as subset.
    So total of 32 subsets.
    Last edited by OReilly; December 5th 2006 at 03:42 PM. Reason: Error in number of subsets
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  3. December 5th 2006, 03:15 PM #3
    Plato
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    OReilly do you know what a take-home test means?
    Don’t you think that a person should do her/his own work?
    But anyway you missed one!
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  4. December 5th 2006, 03:23 PM #4
    OReilly
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    Quote Originally Posted by Plato View Post
    OReilly do you know what a take-home test means?
    Don’t you think that a person should do her/his own work?
    But anyway you missed one!
    Of course, but take-home can mean "go on Internet from your computer in home and post test on MathHelpForum to do it someone for you at home"!

    What did I missed?
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  5. December 5th 2006, 03:42 PM #5
    Plato
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    Quote Originally Posted by OReilly View Post
    What did I missed?
    Well let's let fatcrow200 guess at that one!
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  6. December 5th 2006, 03:44 PM #6
    OReilly
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    Quote Originally Posted by Plato View Post
    Well let's let fatcrow200 guess at that one!
    No, he can't. I already corrected myself.
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