14. The amount of active ingredient of medicine ingested by the body, A, in milligrams is a function of time, t, in hours after the medicine has been taken is given by () = / ( ^ ).

a) Determine the average rate of change for the first three hours after the medicine is ingested.

b) Explain what your result in part a) implies about the amount of active ingredient of the medicine in the body.

c) Estimate the instantaneous rate of change 4 hours after the medicine has been ingested,