Answer:
Dimensions: 75.3778 ft and 66.3325 ft
Minimum price: $1658.31
Step-by-step explanation:
Let's call the length of the parking area 'x', and the width 'y'.
Then, we can write the following equations:
-> Area of the park:
x * y = 5000
-> Price of the fences:
P = 2*x*5.5 + y*5.5 + y*7
P = 11*x + 12.5*y
From the first equation, we have that y = 5000/x
Using this value in the equation for P, we have:
P = 11*x + 12.5*5000/x = 11*x + 62500/x
To find the minimum of this function, we need to take its derivative and then make it equal to zero:
dP/dx = 11 - 62500/x^2 = 0
x^2 = 65000/11
x = 250/sqrt(11) = 75.3778 ft
This is the x value that gives the minimum cost.
Now, finding y and P, we have:
x*y = 5000
y = 5000/75.3778 = 66.3325
P = 11*x + 62500/x = $1658.31