Math
posted by Anonymous .
If Steve has 120 feet of fence to make a rectangular kennel and he will use his house on one side, how would the dimensions be found for a kennel with the greatest area be found?

Math 
Damon
L + 2 w = 120
A = L w
A = (120 2w)w = 120 w  2 w^2
that is parabola opening down, find the vertex (I assume you do not know calculus which would be easier)
2 w^2 + 120 w = A
complete square
w^2  60 w = A/2
w^2  60 w + 30^2 = A/2 + 900
(w30)^2 = A/2 + 900
so
w = 30
then L = 120  60 = 60 
Math 
bobpursley
Area= LW
Perimeter= 2L+ W
dArea/dL= W + dW/dl
the last term you get from taking the derivative of the perimeter equation
0 (perimeter is constant)=2 + dW/dl
so put that in the darea/dl, set to zero, and solve for W. 
Math 
Anonymous
Thanks
Respond to this Question
Similar Questions

Basic college math
A rectangular kennel measures 26 1/2 feet by 20 1/4 feet. Find the area of the kennel in square feet. 
Math
A dog kennel owner needs to build a dog run (rectangular area) adjacent to a kennel cage (so that it is in the shape of a rectangle, but only three sides need to be built one long side is already there). The short side walls of the … 
Calc.
A dog kennel owner needs to build a dog run (rectangular area) adjacent to a kennel cage (so that it is in the shape of a rectangle, but only three sides need to be built one long side is already there). The short side walls of the … 
Data Management
A kennel is to be enclosed with a 20m of fencing. The length of the kennel is to be an integer length and is to be chosen randomly. What is the expected area of the kennel? 
Math
A gardener has 120 ft of fencing to fence in a rectangular garden. one side of the garden is bordered by a river and so it does not need any fencing. 1. what dimensions would guarantee a garden with an area of 1350 ft^2? 
algebra
A gardener has 120 ft of fencing to fence in a rectangular garden. one side of the garden is bordered by a river and so it does not need any fencing. a. what dimensions would guarantee a garden with an area of 1350 ft ^2 b. what dimensions … 
math
the area of a dog kennel is 20 square feet. If the length of the kennel is 4 feet, wha is the width of the kennel? 
Math2
Lacy has $600 set aside to build a rectangular exercise kennel for her dogs. She will buy fencing material for $15/ft. Because the side of an existing barn will be used for one of the sides of the kennel, only three sides need to be … 
Math(Reiny Please Help)
Lacy has $600 set aside to build a rectangular exercise kennel for her dogs. She will buy fencing material for $15/ft. Because the side of an existing barn will be used for one of the sides of the kennel, only three sides need to be … 
math
3) You are fencing a rectangular puppy kennel with 25 ft of fence. The side of the kennel against your house does not need a fence. This side is 9 ft long. Find the dimensions of the kennel. 4) A gardener is planning a rectangular …