Finding a function

Question

Help! Building a fence adjacent to a road and the fence along the road has to be stronger and costs $5 per foot. The fencing on the other sides cost $3 per foot. The area of the garden you are fencing is 2000 square feet. Since square maximizes area, using square what function would I use in terms of cost of its sides?

Answer 1

sqrt(2000) = sqrt(5 * 400) = 20*sqrt(5)

($5+3+3)*20*sqrt(5) = 11*20*sqrt(5) = 220*sqrt(5) = 491.93

Answer 2

sqrt(2000) * ( 5+3+3) = 11*sqrt(2000)

which is approximately is $491.94