Q:

justin wants to use 376 ft of fencing to fence off the greatest possible rectangular area for a garden. what dimensions should he use? what will be the area of the graden?A. 92 x 96; 8832ft B. 93 x 95; 8835ft c. 94 x 94; 8836ft d. 89 x 99; 8811ft

Accepted Solution

A:
Let the length be x and the width be y
the perimeter of the rectangle will be:
2x+2y=376
thus 
y=188-x
thus the area will be:
A(x)=x(188-x)
A(x)=188x-x^2

For maximum Area A'(x)=0
from Area we shall have
A'(x)=188-2x=0
solving for x we get:
x=94
thus the width will be:
188-94=94
thus for maximum area the length=94 ft and width=94 ft
Area=94*94=8836 ft^2
thus the answer is:
c. 94 x 94; 8836ft