The amount of medicine in the bloodstream of a patient decreases roughly exponentially. Here is the graph representing f, an exponential function that models the medicine in the body of a patient, t hours after an injection is given. 1. Use a graph to estimate f(1/3) and explain what it tells us in this situation.
2. After one hour, 0.75 mg of medicine remains in the bloodstream. Find an equation that defines f.