Answer:
The value is
Step-by-step explanation:
From the question we are told that
The area of the rectangular pen is
The cost of material used to make one side is
The cost of material used to make the other sides is
Now , the fence to be build around the rectangular pen has four sides, the first opposite sides are equal, let assume each of the to be x yard and the other opposite sides are also equal as well let assume of the to be y yard
So the cost is mathematically represented as
=>
=>
Now the area of the fence is mathematically represented as
=>
=>
=>
Now differentiating
At minimum
So
Now substituting for x in the equation above to obtain minimum cost
