Answer:
Length of the rectangle = 9.58 feet and width = 27.14 foot
Step-by-step explanation:
Let the length of the rectangular area is = x feet
and the width of the area = y feet
Area of the rectangle = xy square feet
Or xy = 260
y = -------(1)
Cost to fence the three sides = $3 per foot
Therefore cost to fence one length and two width of the rectangular area
= 3(x + 2y)
Similarly cost to fence the fourth side = $14 per foot
So, the cost of the remaining length = 14x
Total cost to fence = 3(x + 2y) + 14x
Cost (C) = 3(x + 2y) + 14x
C = 3x + 6y + 14x
= 17x + 6y
From equation (1)
C =
Now we take the derivative,
C' = 17 -
To minimize the cost of fencing,
C' = 0
17 - = 0
= 17
x = 9.58 foot
and y =
y = 27.14 foot