1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Optimization - area of rectangle

  1. Jan 11, 2010 #1
    1. The problem statement, all variables and given/known data
    If the perimeter of a rectangle is fixed in length, show that the area of the rectangle is greatest when it is square

    2. Relevant equations

    3. The attempt at a solution
    if the perimeter is fixed in length, then 2x + 2y = c
    then no idea to continue from there
  2. jcsd
  3. Jan 11, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper

    Re: differentiation

    Ok so far. Now you want to maximize x*y, right? Eliminate one of the variables using the perimeter condition and differentiate, etc.
  4. Jan 11, 2010 #3


    User Avatar
    Homework Helper

    Re: differentiation

    So what is the area A in terms of x and c?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook