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Math Help - any examples to show d2y/dx2 of max/min point can be 0

  1. #1
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    any examples to show d2y/dx2 of max/min point can be 0

    Any good examples showing {d2y}/{dx2} of max/min point can be 0?

    Thanks.
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  2. #2
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    y = ax +b

    Try this one.
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  3. #3
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    Quote Originally Posted by sa-ri-ga-ma View Post
    y = ax +b

    Try this one.
    the qn is max or min point, not straight line.
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  4. #4
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    Quote Originally Posted by stupidguy View Post
    Any good examples showing {d2y}/{dx2} of max/min point can be 0?

    Thanks.
    y = x^(2n) where n > 1.
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    Quote Originally Posted by mr fantastic View Post
    y = x^(2n) where n > 1.
    Can I show the 3 graphs in LATEX?
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  6. #6
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    Hello, stupidguy!

    \text{Any good examples showing }\frac{d^2y}{dx^2}\text{ of max/min point can be 0?}

    mr fantstic nailed it!


    y \:=\:x^4 is shaped like a parabola, but rises more steeply
    . . and is "fatter" near the origin.


    Code:
                  |
      *           |           *
                  |
                  |
       *          |          *
                  |
        *         |         *
         *        |        *
           *      |      *
              *   |   *
    - - - - - - - * - - - - - - -
                  |

    There is a minimum at (0,0).

    The concavity is 0 because the curve "flattens" slightly there.

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  7. #7
    MHF Contributor ebaines's Avatar
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    Here's another:
    <br />
y = \frac x 2 - \frac {sin 2 x} 4<br />

    You get
    <br />
y' = sin^2 x<br />
    <br />
y'' = 2 sinx\ cosx<br />
    any examples to show d2y/dx2 of max/min point can be 0-graph3.jpg
    Attached Thumbnails Attached Thumbnails any examples to show d2y/dx2 of max/min point can be 0-graph3.jpg  
    Last edited by ebaines; September 10th 2010 at 12:19 PM.
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  8. #8
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    how did you plot a graph? did you use latex?
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  9. #9
    MHF Contributor ebaines's Avatar
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    Quote Originally Posted by stupidguy View Post
    how did you plot a graph? did you use latex?
    Maybe there's an easier way, but what I do is make the graph in Excel, then take a screen shot of the graph, save it as a jpg, then use the Attachments tool under "Go Advanced."
    Attached Thumbnails Attached Thumbnails any examples to show d2y/dx2 of max/min point can be 0-graph3.jpg  
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  10. #10
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    Quote Originally Posted by ebaines View Post
    Maybe there's an easier way, but what I do is make the graph in Excel, then take a screen shot of the graph, save it as a jpg, then use the AtTtachments tool under "Go Advanced.
    I am so touched that you did so much to explain to me without any return.
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