A manufacturer finds that in producing x units per day (for 0 < x < 100), three different kinds of cost are involved:

a. A fixed cost of $1,200 per day in wages

b. A production cost of $1.20 per day for each unit produced

c. An ordering cost of 100/x² dollars per day Express the total cost as a function of x and determine the level of production that results in minimal total cost.