1.   For find the number of units x that produces the minimum average cost per unit

2.   For find the number of units x that produces the minimum average cost per unit

3.  Cost A power station is on one side of a river that is 0.5 miles wide, and a factory is 6 miles downstream on the other side of the river (see figure). It costs $6 per foot to run power lines overland and $8 per foot to run them under water. Find the most economical path for the power line from the power station to the factory.