[SCHEMES PT2] [200points total]
2. Factory in Seattle
Seattle’s factory is the company’s newest. It was constructed with sustainable building techniques and
materials, so its cost structure has been affected in several ways. The Seattle plant uses a mix of solar
power (not very reliable with so many clouds), thermal power, and wind. It has an array of batteries, so at
the beginning of each production day, there is “free” stored energy that can produce up to 8,000 units. Of
course, energy is just one factor of the cost of production, but it is significant.
The cost function for the Seattle factory is given by the following piecewise function. That is, ()is the
cost function, where is the number of units produced. The plant’s maximum capacity is 42,000 units per
day.
() = {
0.35 ≤ 8,000
0.75 8,000 < ≤ 20,000
0.83 − (

200,000) 20,000 < ≤ 42,000
Student Guide (continued)

a) Sketch a graph to model Seattle’s cost structure over the domain [0, 42000]. Be sure to label the
axes and any endpoints where the graph breaks.
b) Describe the function over each part of its domain. State whether it is constant,
increasing, or decreasing, and state the slope over each part