Sunday

January 25, 2015

January 25, 2015

Posted by **Anonymous** on Tuesday, October 25, 2011 at 2:48pm.

- Calculus -
**Steve**, Tuesday, October 25, 2011 at 3:24pmIf each pen has width x and length y (against the barn),

the area is 4xy, and the fence used is 5x+8y

So, each pen has area 100.

p = 5x + 8(100/x) = 5x + 800/x

dp/dx = 5 - 800/x^2

dp/dx = 0 when x = √160 = 4√10

x = 4√10

y = 25/√10

- Calculus -
**Steve**, Tuesday, October 25, 2011 at 3:27pmNow, if the barn is used as one wall of the pen, meaning only 3 sides have to be fenced, then

p = 5x+4y = 5x + 4(100/x) = 5x + 400/x

p' = 5 - 400/x^2

p' = 0 at x = 4√5

y = 25/√5

**Answer this Question**

**Related Questions**

Calculus - A rancher plans to make four identical and adjacent rectangular pens ...

Math: pre calculus - a barn is 150 feet long and 75 feet wide. the owner has 240...

Calculus - A rancher wants to make a rectangular pen to house her animals. She ...

College Algebra - A rancher needs to build four identical pens for his animals ...

Calculus Word Problem - A farmer wishes to build a fence for 6 adjacent ...

Calculus Follow Up - A farmer wishes to build a fence for 6 adjacent rectangular...

algebra - Ian wants to build a rectangular pen for his animals. One side of the ...

math - a rectangular pen is to be constructed alongside a barn using 120 feet of...

calculus - A rancher has 1000 feet of fencing with which to enclose two adjacent...

Calculus 2 - A farmer wishes to build a fence for 6 adjacent rectangular pens. ...