Pre Calc!
posted by Hayli .
A drug is eliminated from the body through urine. Suppose that for a dose of 10 milligrams, the amount A(t) remaining in the body t hours later is given by A(t)=10(0.8)^t and that in order for the drug to be effective, at least 2 milligrams must be in the body.
(a) Determine when 2 milligrams is left in the body.
(b) What is the half-life of the drug?