Answer:
The dimension that maximizes area is 144ft by 144ft
Step-by-step explanation:
Given
[tex]P = 576[/tex] -- perimeter
Required
The dimension that gives maximum area
Perimeter is calculated as:
[tex]P= 2 * (L + W)[/tex]
So, we have:
[tex]2 * (L + W) = 576[/tex]
Divide through by 2
[tex]L + W = 288[/tex]
Make L the subject
[tex]L = 288 -W[/tex]
Area is calculated as:
[tex]A = L * W[/tex]
Substitute [tex]L = 288 -W[/tex]
[tex]A = (288 - W) * W[/tex]
Open bracket
[tex]A = 288W - W^2[/tex]
Differentiate A with respect to W
[tex]A' = 288 - 2W[/tex]
Set to 0 to calculate W
[tex]288 - 2W = 0[/tex]
Collect like terms
[tex]2W = 288[/tex]
Divide by 2
[tex]W = 144[/tex]
Recall that:
[tex]L = 288 -W[/tex]
[tex]L = 288 - 144[/tex]
[tex]L = 144[/tex]
