Many people take aspirin on a regular basis as a preventive measure for heart disease. Suppose a person takes 80 mg of aspirin every 24 hours. Assume also that aspirin has a half-life of 24 hours; that is, every 24 hours, half of the drug in the blood is eliminated.

a. Find a recurrence relation for the sequence {d_n} that gives the amount of drug in the blood after the nth dose, where d₁ = 80.

b. Using a calculator, determine the limit of the sequence. In the long run, how much drug is in the person’s blood?

c. Confirm the result of part (b) by finding the limit of {d_n} directly.