Results 1 to 5 of 5

Math Help - Point of extremum

  1. #1
    Newbie
    Joined
    Sep 2011
    Posts
    9

    Point of extremum

    If f(x) = Mod(x), 0<Mod(x)<=2
    1 x=0
    Is there any local extremum at x=0.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    14,973
    Thanks
    1121

    Re: Point of extremum

    By "mod(x)", do you mean "absolute value of x", |x|?

    If so, your function is f(x)= |x| for -2\le x< 0 and 0< x\le 2 while f(0)= 1. Yes, x= 0 is a local maximum since f(0)= 1 is larger than f(x) for x close to, but not equal to 0.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor FernandoRevilla's Avatar
    Joined
    Nov 2010
    From
    Madrid, Spain
    Posts
    2,162
    Thanks
    44

    Re: Point of extremum

    Quote Originally Posted by deepak View Post
    If f(x) = Mod(x), 0<Mod(x)<=2 1 x=0Is there any local extremum at x=0.
    If you mean f(x)=\begin{Bmatrix} |x| & \mbox{ if }& 0<|x|<2\\1 & \mbox{if}& x=0\end{matrix} , then there is a local maximum at x=0 because f(0)\geq f(x) in a neighborhood of 0 .


    Edited: Sorry, I didn't see HallsofIvy post.
    Last edited by FernandoRevilla; December 27th 2011 at 04:41 AM.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Apr 2005
    Posts
    14,973
    Thanks
    1121

    Re: Point of extremum

    It was probably posted while you were typing your resonse!
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor FernandoRevilla's Avatar
    Joined
    Nov 2010
    From
    Madrid, Spain
    Posts
    2,162
    Thanks
    44

    Re: Point of extremum

    Quote Originally Posted by HallsofIvy View Post
    It was probably posted while you were typing your resonse!
    Both of us at 2:26 PM, but you are helper, so your post appeared before mine
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Extremum of f
    Posted in the Calculus Forum
    Replies: 5
    Last Post: March 17th 2011, 08:04 PM
  2. find all extremum points
    Posted in the Calculus Forum
    Replies: 4
    Last Post: November 2nd 2009, 06:54 PM
  3. Local extremum (2 variables)
    Posted in the Calculus Forum
    Replies: 3
    Last Post: June 2nd 2009, 07:02 AM
  4. extremum
    Posted in the Algebra Forum
    Replies: 9
    Last Post: August 1st 2007, 04:31 AM
  5. multivarible extremum point
    Posted in the Calculus Forum
    Replies: 5
    Last Post: February 7th 2007, 10:29 PM

Search Tags


/mathhelpforum @mathhelpforum