Rational Functions and Rational Inequalities Section 4.5 379 Solve the following application problems. 69. Joan raises rabbits, and the population 71. At t minutes after injection, the of her rabbit colony follows the formula concentration (in mg/L) of a certain drug in the bloodstream of a patient is given by the formula 200t p(t) = t+1 where t20 represents the number of months since she began. 20t c(t)= t2 +1 a. Sketch the graph of p(t) for t20. a. Sketch the graph of c(t) for t20. b. What happens to Joan's rabbit population in the long run? b. What happens to the concentra- tion of the drug in the long run? 70. If an object is placed a distance x from a lens with a focal length of f, the image of the object will appear a distance y on the opposite side of the lens, where x, f, and y are related by the equation х y f a. Express y as a function of x and f. b. Graph your function for a lens with a focal length of 30 mm (f = 30). What happens to y as the distance x increases? %3D Image Object