Results 1 to 2 of 2

Math Help - functions increasing but product of two are not?

  1. #1
    Newbie
    Joined
    Sep 2009
    Posts
    15

    functions increasing but product of two are not?

    Show that both f(x) =x and g(x)=x-1 are strictly increasing on I =[0,1], but their product fg is not increasing on I
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Oct 2005
    From
    Earth
    Posts
    1,599
    Quote Originally Posted by gixxer998 View Post
    Show that both f(x) =x and g(x)=x-1 are strictly increasing on I =[0,1], but their product fg is not increasing on I
    It looks like you can show this with basic derivative properties. Show f and g have a positive slope on the interval first. Then take the product and differentiate. You should get a critical point in the interval of [0,1]
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. increasing and decreasing functions
    Posted in the Calculus Forum
    Replies: 3
    Last Post: May 15th 2010, 02:11 AM
  2. increasing functions prove strictly increasing
    Posted in the Differential Geometry Forum
    Replies: 2
    Last Post: May 14th 2010, 03:19 PM
  3. increasing & decreasing functions
    Posted in the Pre-Calculus Forum
    Replies: 0
    Last Post: December 16th 2008, 07:18 AM
  4. increasing functions
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: December 3rd 2008, 03:21 PM
  5. increasing functions
    Posted in the Calculus Forum
    Replies: 3
    Last Post: November 5th 2006, 10:18 AM

Search Tags


/mathhelpforum @mathhelpforum