We will have an absolute maximum (or minimum) at provided f(c) is the largest (or smallest) value that the function will ever take on the domain that we are working on. Also, when we say the âdomain we are working onâ this simply means the range of xâs that we have chosen to work with for a given problem.
Thompson's slope is about one percent, so each structure manages a zone of about nine acres. At $500 to $2,000 per structure, the drainage water management structures only added about five to 15 percent to the cost of upgrading the field's century-old drainage system.t $500 to $2,000 per structure, the drainage water management structures only added about five to 15 percent to the cost of upgrading the field's century-old drainage system.
1 Having a landscaper or other professional install outdoor French drains can cost $10-$30 a linear foot but averages about $25 /foot depending on depth and width (typically 12-24 deep and 6-18 wide), and local rates.2  A French drain 30'-50' long might cost $300-$1,500, with prices averaging about $750-$1,250. A do-it-yourself dry well can cost $5-$50, or $90-$380 for a DIY installation of a prefabricated plastic model; having a concrete drywell professionally installed can cost $300-$5,000 or more. 2  Installing a rain garden can cost $100-$750 for a do-it-yourself project of 150 square feet.