A company is planning to manufacture PDAs (personal digital assistants). The fixed cost will be $400,000 and it will cost $20 to produce each PDA. Each PDA will be sold for $100.

a. Write the cost function, C, of producing x PDAs.

b. Write the revenue function, R, from the sale of x PDAs.

c. Write the profit function, P, from producing and selling x PDAs.

d. Determine the break-even point. Describe what this means.