Profit: The monthly profit P for a widget producer is a function of the number n of widgets sold. The formula is Here P is measured in thousands of dollars, n is measured in thousands of widgets, and...

Profit: The monthly profit P for a widget producer is a function of the number n of widgets sold. The formula is

Here P is measured in thousands of dollars, n is measured in thousands of widgets, and the formula is valid up to a level of 15 thousand widgets sold.

a. Make a graph of P versus n.

 b. Calculate P (1) and explain in practical terms what your answer means.

c. Is the graph concave up or concave down? Explain in practical terms what this means.

d. The break-even point is the sales level at which the profit is 0. Find the break-even point for this widget producer.