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    I've got a question asking to find the range of f for the function below

    f: x |-> x^2 -2x + 3 , x e R, 0 <= x <= 4

    I sub in x for 4 and get 11, but don't know where to go from there.
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    (Original post by MJ_23)
    I've got a question asking to find the range of f for the function below

    f: x |-> x^2 -2x + 3 , x e R, 0 <= x <= 4

    I sub in x for 4 and get 11, but don't know where to go from there.
    why not draw the graph, and find the minimum point?
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    (Original post by MJ_23)
    I've got a question asking to find the range of f for the function below

    f: x |-> x^2 -2x + 3 , x e R, 0 <= x <= 4

    I sub in x for 4 and get 11, but don't know where to go from there.
    Complete the square, f(x) = (x-1)^2 + 2
    (x-1)^2 > 0 for all x so f(x)>2
    min pt is (1,2) so range is f(x)>2
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    (Original post by MJ_23)
    I've got a question asking to find the range of f for the function below

    f: x |-> x^2 -2x + 3 , x e R, 0 <= x <= 4

    I sub in x for 4 and get 11, but don't know where to go from there.
    complete the square to get f(x)=(x-1)²+2.
    so the minimum point is when x=1,and f(x)=2.
    Or u can find f': f'(x)=2x-2.At minimum f'(x)=0 therefore x=1 so f(x)=2.
    Since f(x) must lie above or on this minimum point the range is f(x)≥2
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    max value for f is when x = 4
    f(x=4) = 4² - 2.4 + 3
    f_max = 11

    therefore range of f is
    2 <= f <= 11
    =========
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    (Original post by Fermat)
    max value for f is when x = 4
    f(x=4) = 4² - 2.4 + 3
    f_max = 11

    therefore range of f is
    2 <= f <= 11
    =========
    are u sure?:
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    (Original post by IntegralAnomaly)
    are u sure?:
    Yep.
    the range, or domain, of x is given as
    0 <= x <= 4

    That means that x cannot take a value less than 0 or greater than 4, so must be constrained to lie within the lines x=0 and x=4.
    The minimum of the curve gives the lower end of the range of f, i.e. f=2.
    Since the value of x cannot exceed 4 then max f is given by f(x=4) = 11.
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    (Original post by Fermat)
    Yep.
    the range, or domain, of x is given as
    0 <= x <= 4

    That means that x cannot take a value less than 0 or greater than 4, so must be constrained to lie within the lines x=0 and x=4.
    The minimum of the curve gives the lower end of the range of f, i.e. f=2.
    Since the value of x cannot exceed 4 then max f is given by f(x=4) = 11.
    Oops,i didn't see that bit!sorry
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    (Original post by IntegralAnomaly)
    Oops,i didn't see that bit!sorry
    no prob
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    (Original post by Fermat)
    no prob
    sorry fermat but you posted 2 sites about latex a while ago,what was the other one?(not the one u pm me).
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    What's latex?
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    (Original post by Bhaal85)
    What's latex?
    have u heard of mathtype?this is ten times better:http://www.latex-project.org/.
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    (Original post by IntegralAnomaly)
    have u heard of mathtype?this is ten times better:http://www.latex-project.org/.
    Confused by it all, which is the one I need to be able to use mathematical signs, I'm on WinXP, which do I download?
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    (Original post by IntegralAnomaly)
    sorry fermat but you posted 2 sites about latex a while ago,what was the other one?(not the one u pm me).
    When i first read this post, i thought you were talking about latex material (as in gloves) and i thought that was VERY random!!! Now i just feel stupid
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    (Original post by Silly Sally)
    When i first read this post, i thought you were talking about latex material (as in gloves) and i thought that was VERY random!!! Now i just feel stupid
    How silly. lol (If its any consolation, I too thought that when it was first mentioned weeks before).
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    (Original post by Bhaal85)
    Confused by it all, which is the one I need to be able to use mathematical signs, I'm on WinXP, which do I download?
    i recommend u start using latex after ur exams finish because it is useful at uni,assuming that ur doin a science based degree.Here's an example of how it looks:http://mathworld.wolfram.com/GammaFunction.html.While mathtype is crap.
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    (Original post by IntegralAnomaly)
    sorry fermat but you posted 2 sites about latex a while ago,what was the other one?(not the one u pm me).
    I've got three sites I've used:
    Beginning Latex
    Getting Started with LaTeX
    LaTeX Tutorial

    The last one is mainly for instructing unix users in setting up and runnnng latex on a Unix system but has somwe useful latex info as well.

    enjoy!
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    (Original post by Bhaal85)
    Confused by it all, which is the one I need to be able to use mathematical signs, I'm on WinXP, which do I download?
    To set up a simple latex system, goto http://www.miktex.org and click on the [setup] link to download the small MikTex compiler. Just run the exe file and it will install the package.
    Like mikesgt2, I use an editor called TeXnicCenter, which makes editing and compiling documents easier, you can find it here: http://www.texniccenter.org (look for the Download link in the panel on the left)
    When you install this, you will be asked for a file viewer (for the dvi files), click on the Browse button, and navigate to C:\texmf\miktex\bin and select yap.exe.
 
 
 
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