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Homework Help: Optimization set-up

  1. Mar 25, 2006 #1
    We're doing optimization problems and I was just wondering if I set this one up right:

    What are the dimensions of a rectangle with an area of 64m^2 and the smallest possible perimeter?

    Area=xy
    64=xy
    y=64/x
    Perimeter=2x+2y
    = 2x+2(64/x)
    = 2x+128/x
     
  2. jcsd
  3. Mar 25, 2006 #2
    Simple. In this case you have just to find the minimum value of the perimeter function for values of x > 0, then you find y and have the dimensions of the rectangle with the smallest perimeter.

    Anyway, here is the plot of the functions. Pink - Perimeter; Blue - Area.

    http://img296.imageshack.us/img296/3231/plot553br.png [Broken]
     
    Last edited by a moderator: May 2, 2017
  4. Mar 25, 2006 #3
    We just started so we're not at THAT level yet, but thanks anyways D8
     
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