Airline Net Income The following graph shows the approximate annual after-...

Airline Net Income The following graph shows the approximate annual after-tax net income P(t), in millions of dollars, of Delta Air Lines for 2005–2009 (t = 0 represents 2005):

a. Estimate P(0), P(1), and P(3.5) to the nearest 100. Interpret your answers.

b. At which of the following values of t is P(t) increasing most rapidly: 0, 0.5, 1, 2.5, 3.5? Interpret the result.

c. At which of the following values of t is P(t) decreasing most rapidly: 0, 0.5, 1, 2.5, 3.5? Interpret the result.