First, express the cost of the fencing as an equation in terms of L. Be sure to list restrictions. Then determine the dimensions of L and W that minimize the cost.

Question

A rectangular area of 1000 ft2 is to be enclosed by a fence in combination with a pre-existing wall. The wall forms the North boundary and is 150 ft. in length. You may use as much (or as little) of the wall as necessary to form the enclosure. The fencing for the South, East and West boundaries still needs to be built. The fencing to be used for the East and West sides costs 5 times as much per unit length as the fencing to be used on the South side. Draw and label an appropriate diagram, using L for the length of the North/South sides and W for the length of the East/West sides. Each side must be at least 5 ft. in length. First, express the cost of the fencing as an equation in terms of L. Be sure to list restrictions. Then determine the dimensions of L and W that minimize the cost.

Answer 1