Answers to Exercise2 questions

Assignments for Monday, Sept. 6, 1999

problems: 2.7, (page 27), 2.8, 2.9, 2.10, , 2.11, 2.12, 2.13 in your text.

profits=revenue - cost; this is the accounting definition of cost. Apply this definition to the equations in problem 4. pr:= below signifies profits.

> pr:=x-(x/3+6);

> plot(pr,x=0..40,title=profits);

> solve(pr,x);

As seen from the graph or (the solution), at x=9, profits are zero, but beyond x=9, profits are positive. When x=9, we are at the breakeven point. Likewise, the answers to parts b, c, and d can be easily worked out.

Breakeevn points for b is at x= 3/2, for c is at x=3.75, and for d is at x=5.2.