A doctor has prescribed a drug for a patient. Let A be the amount the patient takes each time and c be the fraction of dug cleared by the body between doses. Define an to be the amount of drug in the body immediately after taking the nth dose.
a. Write a difference equation for an.
b. Find the equilibrium of the difference equation in part a.
c. Determine under what conditions the equilibrium amount of drug in the body (right after taking a dose) is greater than twice the dose A being taken by the patient.