9. The short run and long run do not correspond to any specific period of calendar time. Explain.

10. What is a production function?

11. Use functional notation to express the production function.

12. What is total product? Describe the shape of the total product curve.

13. Describe the behaviour of total product when marginal product is

a) Rising

b) Positive

c) Positive but falling

d) Negative

14. If labour and capital can be substituted and the wage rate rises, what adjustment will the firm likely make?

15. What is the principle of substitution? What is the relation between this principle and the cost-minimization condition?