City A lies on the north bank of a river that is 1 mile wide. You need to run a phone cable from City A to City B, which lies on the opposite bank a = 5 miles down the river. You will lay Lmiles of the cable along the north shore of the river, and from the end of that stretch of cable you will lay W miles of cable running under water directly toward City B.
Find the amount of cable W that runs under water and the total cost C of the project if you choose L to be 1 mile long. (Round your answers to two decimal places.)
Find the amount of cable that runs under water and the total cost of the project if you choose L to be 3 miles long. (Round your answers to two decimal places.)
What value of L gives the least cost for the project? (Round your answer to two decimal places.)
Find the value of W that corresponds to your answer in part (f). (Round your answer to two decimal places.)
