6. Experiments with a covered cup of coffee show that the temperature in °F) of the coffee can be
modeled by the following equation: f(t) = 112e-0. + 68
-0.080
where time (t) is measured in minutes after the coffee was poured into the cup.
_a. [2] What is the temperature of the coffee at the beginning of the experiment?
_b. [1] What is the temperature of the room?
_c. [5] After how many minutes is the coffee 140°F? Give your answer to 3 decimal
places.

f(t)
-0.080
= 112e-0.
+ 68