A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Suppose that 320 feet of fencing are available to enclose a rectangular field and that one side of the field must be given double fencing. What are the dimensions of the field of maximum area?

  • This Question is Closed
  1. darthsid
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Let one side be x, and the other side be y. Now, let the side with double fencing be x. So, the perimeter is 3x + 2y, which is given to be 320. We need to maximize the area, which is xy. From the perimeter, y = 160-3/2x so, area = xy = 160x - 3/2(x^2) now, using differentiation, find points where d(area)/dx has maxima.

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How is differentiation to be used?

  3. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Do you mean like ax^2+bc+c=0

  4. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Please help

  5. darthsid
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yeah, just like that. Find out values of x where d(area)/dx is zero. You can differentiate the area expression the same way you would differentiate a generic quadratic expression like ax^2+bx+c. The area expression I mentioned above can be written like ax^2 + bx + c, where a = -3/2 b = 160 c = 0

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Suppose that a rectangular area is to be fenced, except one side must be fenced twice because it runs along a river.  If the amount of fencing is 320 yards in length, what is the maximum area that can be fenced? I see this question answered below, but We need to maximize the area, which is xy. From the perimeter, y = 160-3/2x so, area = xy = 160x - 3/2(x^2) - why is this x squared? and once you derive the ax^2+bx+c=0 formula, how do you maximize the area?

  7. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.