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
Fig: 1