4. A power company and a factor are located on opposite sides of a river. The power company is 3000 m down the river (the river is 500 m wide). Power lines along the ground costs $20 per meter and underwater power lines cost $80 per meter. What path should the lines follow in order to minimize the cost? 500m 3000 m X 5. The company also makes open-top trays from the same 20 cm by 30 cm rectangular flat sheet by cutting squares off of the corners on only one end of the sheet and folding up three sides. How big should the squares be to produce a tray of maximum volume? 0.03 0.18x-11.52 11.522=0 0.18x = 11.52 x = 11.52 X 64 X=4 3. A business office wants to put in Norman windows, which are windows in the shape of rectangles capped by a semicircle (see below). These windows will have special decorative trim purchased by the length, so it will be beneficial to get the most light for the least perimeter of window. If 10 feet of trim is allotted for each Norman window (including the segment between the semicircle and the rectangle), what dimensions maximize their area?