calculus
posted by Liz .
A power station and a factory are on opposite sides of a river 50 feet wide. A power line must be run from the station to the factory. It costs 25 dollars per foot to run the cable in the river and $15 per foot on land. Express the total cost as a function of x, where x represents the distance downstream from the power station to the point where the cable touches land.

assume the line goes on the same side L, the n crosses.
cost=15L+25sqrt(50^2+(Lx)^2 )
Where L is the distance downstream to the factory.
So what is dcost/dx ?
check my thinking. 
i have a similar question but instead of 50 its 60 aqnd 15 is 20
Respond to this Question
Similar Questions

11th Grademath
A power station and a factory are on opposite sides of a river 50 feet wide. A power line must be run from the station to the factory. It costs 25 dollars per foot to run the cable in the river and $15 per foot on land. Express the … 
Math
Power Plant on the River Problem As the construction manager for the Lightem Up Power Company , you make decisions to hep minimize costs of the company's construction projects. Today you've been asked to determine the path of a pipe … 
math
A pottery factory needs to connect with the main gas pipe line. This pipeline is on the other side of a stream. A gas line must be run from the main line junction to the factory at the lowest possible cost. It costs $12.50 per foot … 
Calculus Optimization
An electric utility is required to run a cable from a transformer station on the shore of a lake to an island. The island is 6 km from the shore and the station is 12 km down the shoreline from a point opposite the island. It costs … 
calculus
A power station is on one side of a river that is 0.5 mile wide, and a factory is 5.00 miles downstream on the other side of the river. It costs $15 per foot to run overland power lines and $23 per foot to run underwater power lines. … 
Applied Calculus
An underground electricity cable is to be laid between two boat docks on opposite banks of a river. One boat dock is 600 feet downstream from the other. The river is 200 feet wide. If the cost of laying the cable is $50 per foot under … 
math
A power station is on one side of a river that is 3/4 mile wide, and a factory is 8 miles downstream on the other side of the river. It costs $24 per foot to run power lines over land and $30 per foot to run them under water.(1 mile … 
Calculus 1
a power station needs to supply power lines to a location 10 miles downstream and on the other side of a river that is 0.75 miles wide. Power lines cost $7 per foot on land and $10 per foot under water. What is the most economical … 
Calculus
An island is 3 mi from the nearest point on a straight shoreline; that point is 6 mi from a power station. A Utility company plans to lay electrical cable underwater from the island to the shore and then underground along … 
Calculus
A factory is located on one bank of a straight river that is 2000 m wide. On the opposite bank but 4500 m downstream is a power station from which the factory draws its electricity. Assume that it costs $3 per meter to lay an underwater …