Results 1 to 4 of 4

Math Help - Calculus help! Min Max problem

  1. #1
    Newbie
    Joined
    Nov 2008
    Posts
    5

    Calculus help! Min Max problem

    A printed page is to contain 60cm of typing with clear margins around, of 5 by 3. Find the minimum area of the entire page?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Oct 2007
    Posts
    209
     A=xy
    60=(x-3)(y-5)
    \frac {60}{x-3}=y-5
    \frac {60}{x-3}+5=y
     A=x(\frac {60}{x-3}+5)

    Can you do the rest? It's just a matter of taking the derivative of A and doing the first derivative test.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Eric View Post
    A printed page is to contain 60cm of typing with clear margins around, of 5 by 3. Find the minimum area of the entire page?
    Minimise A = (x + 10)(y + 6) subject to the condition xy = 60.
    Last edited by mr fantastic; November 29th 2008 at 09:56 PM. Reason: Yes I did mean y + 6
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Oct 2007
    Posts
    209
    Oops, I forgot to take both sides into consideration

     A=xy
    60=(x-6)(y-10)
    \frac {60}{x-6}=y-10
    \frac {60}{x-6}+10=y
     A=x(\frac {60}{x-6}+10)

    Can you do the rest? It's just a matter of taking the derivative of A and doing the first derivative test.

    mr fantastic's method works too, except I think he means y+6
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculus problem
    Posted in the Calculus Forum
    Replies: 1
    Last Post: January 22nd 2010, 08:30 PM
  2. Calculus problem
    Posted in the Calculus Forum
    Replies: 4
    Last Post: February 23rd 2009, 11:44 AM
  3. Replies: 1
    Last Post: June 7th 2008, 11:47 AM
  4. Calculus Problem
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 2nd 2008, 08:08 AM
  5. New Calculus Problem
    Posted in the Calculus Forum
    Replies: 3
    Last Post: October 29th 2006, 11:37 AM

Search Tags


/mathhelpforum @mathhelpforum