The half life of an antibiotic in the bloodstream is 12 hr If an initial dose of 20 mg is administered the quantity left after thours is modeled by Q t 20e 0 0578t for t 0 a Find the instantaneous rate of change of the amount of antibiotic in the bloodstream for 0 st 12 hr b How fast is the amount of antibiotic changing at t 0 hr At t 2 hr c Evaluate and interpret lim Q t and lim Q t 1 1 0 a Find the instantaneous rate of change of the amount of antibiotic in the bloodstream for 0 st 12 hr Q t Type an exact answer in terms of e Round to four decimal places as needed