A patient took 200 milligrams of a medicine necessary to fighting an infection. Each hour, 40% of the medicine dissolves in the body. Write a recursive formula that represents how much medicine is in the body after each hour. an = an-1 - 0.4an-1; a1 = 200 an = an-1 - 0.4an-1; do = 200 an = 0.4an-1; do = 200 an = 0.4an-1; a1 = 200