Chapter 12.3, Problem 54E

To determine

To calculate: The point at which the line should begin to yield the minimum total cost. Where, the island is 6 miles from the shore (at point C), and point A is 9 miles from point C. It costs $400 per mile to run the cable on land and $500 per mile underwater. Assume that the cable starts at A, runs along the shoreline, and then angles and runs underwater to the island.