Results 1 to 6 of 6

Math Help - Need guidance with a concavity problem, can't seem to figure it out.

  1. #1
    Newbie
    Joined
    Apr 2011
    Posts
    3

    Need guidance with a concavity problem, can't seem to figure it out.

    the problem is in the attached pdf file.concavity.PDF
    Follow Math Help Forum on Facebook and Google+

  2. #2
    A Plied Mathematician
    Joined
    Jun 2010
    From
    CT, USA
    Posts
    6,318
    Thanks
    4
    Awards
    2
    Questions about concavity are best answered with the second derivative, which you don't seem to have found. I'd recommend finding the second derivative, and then using the second derivative test:

    Need guidance with a concavity problem, can't seem to figure it out.-second-derivative-test-mnemonic.jpg

    As you can see, the plus-sign eyes (second derivative is positive) correspond to concave up. The minus-sign eyes (second derivative is negative) correspond to concave down. The zero eyes (second derivative is zero) is a very confused individual: you could have it concave down (one eyebrow), or concave up (the other eyebrow) or a point of inflection (the mouth). That is, if the second derivative is zero, you don't know what's happening there in terms of concavity.

    Does that help?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2011
    Posts
    3
    Is this right?
    Attached Files Attached Files
    Follow Math Help Forum on Facebook and Google+

  4. #4
    A Plied Mathematician
    Joined
    Jun 2010
    From
    CT, USA
    Posts
    6,318
    Thanks
    4
    Awards
    2
    You are correct.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Apr 2011
    Posts
    3
    Thank you so much.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    A Plied Mathematician
    Joined
    Jun 2010
    From
    CT, USA
    Posts
    6,318
    Thanks
    4
    Awards
    2
    You're welcome! Have a good one.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 0
    Last Post: February 1st 2010, 06:09 AM
  2. Concavity Problem?
    Posted in the Calculus Forum
    Replies: 1
    Last Post: January 8th 2010, 05:39 AM
  3. Curve Sketching - Concavity - Problem 2
    Posted in the Calculus Forum
    Replies: 3
    Last Post: July 6th 2009, 10:52 AM
  4. Curve Sketching - Concavity - Problem 1
    Posted in the Calculus Forum
    Replies: 2
    Last Post: July 6th 2009, 03:57 AM
  5. Concavity problem...what am i doing wrong?
    Posted in the Calculus Forum
    Replies: 7
    Last Post: November 7th 2008, 10:42 PM

Search Tags


/mathhelpforum @mathhelpforum