The nationwide use of public transportation can be modeled using the following function. The year 1996 is represented by t = 0, and P(t) represents passenger trips in millions. P(t) ) = { 0.041. a. Approximately how many passenger trips were there in 1999? in 2004? b. State the domain of the function. 0.35t +7.6 if 0t5 -0.6t+11.6 if 5