A small caf
é sells drip coffee for
$0.90 per cup. On average, it costs the caf
é $0.20 to make a cup of coffee (for grounds, hot water, filters). The caf
é also has a fixed daily cost of
$200 (for rent, wages, utilities).
(a) Let
R,
C, and
P be the caf
é's daily revenue, costs, and profit, respectively, for selling
x cups of coffee in a day. Find formulas for
R,
C, and
P as functions of
x. [Hint: The revenue,
R, is the total amount of money that the caf
é brings in. The cost,
C, includes the fixed daily cost as well as the cost for all
x cups of coffee sold.
P is the caf
é's profit after costs have been accounted for.]
(b) Plot
P against
x.
For what
x-values is the graph below the
x-axis? (Round your answer to the nearest integer.)
For what
x-values is the graph above the
x-axis? (Round your answer to the nearest integer.)
Interpret your results.
When the graph of the profit function is above the x-axis, the café's profits are
, meaning that it is
money. When the graph of the profit function is below the x-axis, the café's profits are
, meaning that it is
money.
(c) Interpret the slope of your graph in practical terms.
Interpret the
y-intercept of your graph in practical terms.
Interpret the
x-intercept of your graph in practical terms.