Purchases of streamed music can be modeled by f (t) = 3.7 + 0.84 ln(t +1), where f (t) is measured in billions of dollars and t is measured in years, with t=0 corresponding to 2012.
a. What was the amount spent by consumers on streamed music in 2014? Use the correct units.
b. How fast was the amount spent by consumers on streamed music changing in 2014?
Use the correct units.