1. On one side of a 1 km-wide river is an electric power plant. On the other side of the river,

5 km upstream, is a factory. It costs $9 per meter to run the cable over land and $15 per

meter to run it under water. Write an expression for the cost function c(x). Use calculus to

solve for x that minimizes cost. Verify by plotting c(x) vs x.

1 Km $15/meter

Power plant

5 Km

$9/meter

Cable is

dashed line

Factory