# Fencing Anyone???

• Nov 1st 2007, 07:47 PM
bobchiba
Fencing Anyone???
A farmer wants to enclose an area of 1500 square metres. Suppose that along the road adjoining his property he would like to use a more expensive fence, and that no fence is needed along one side of the area perpendicular to the road as it is bounded by a river.

Ive made an image to represent this below. Excuse my crude use of paint!.....

my questions are... explain why Y = 1500/X? ,

and how do I show that the quantity to be minimised is
C = 40X + 22500/X ?

http://www.ezyshot.com/out.php/i1270_problem.JPG
• Nov 1st 2007, 07:53 PM
Jhevon
Quote:

Originally Posted by bobchiba
A farmer wants to enclose an area of 1500 square metres. Suppose that along the road adjoining his property he would like to use a more expensive fence, and that no fence is needed along one side of the area perpendicular to the road as it is bounded by a river.

Ive made an image to represent this below. Excuse my crude use of paint!.....

my questions are... explain why Y = 1500/X? ,

the area enclosed by the fence is the area of the rectangle with sides x and y. so A = xy = 1500, since they told us the area is 1500. solving for y gives you y = 1500/x

Quote:

and how do I show that the quantity to be minimised is
C = 40X + 22500/X ?
more information is needed here. you haven't told us the cost of the fence or anything