Respuesta :
Answer: (A) [tex]A=300l-l^{2}[/tex]
(B) Length varies between 1 and 150
(C) Largest area is 22500ft²
Step-by-step explanation: Suppose length is l and width is w.
The rectangular garden has perimeter of 600ft, which is mathematically represented as
[tex]2l+2w=600[/tex]
Area of a rectangle is calculated as
[tex]A=lw[/tex]
Now, we have a system of equations:
[tex]2l+2w=600[/tex]
[tex]A=lw[/tex]
Isolate w, so we have l:
[tex]2w=600-2l[/tex]
w = 300 - l
Substitute in the area equation:
A = l(300 - l)
A = 300l - l²
(A) Function of area in terms of length is given by A = 300l - l²
(B) The practical domain for this function is values between 1 and 150.
(C) For the largest area, we need to determine the largest garden possible. For that, we take first derivative of the function:
A' = 300 - 2l
Find the values of l when A'=0:
300 - 2l = 0
2l = 300
l = 150
Replace l in the equation:
w = 300 - 150
w = 150
Now, calculate the largest area:
A = 150*150
A = 22500
The largest area the fence can enclose is 22500ft².
