T The concentration, C, of phenylbutazone, in micrograms per milliliter (g/mL), in the plasma of a calf injected with this anti-inflammatory agent is given approximately by C(t) = 42.06 -0.01042t, where t is the number of hours after the injection and Osts 90. AC 50- O 40- a a) Given that the model is accurate for Osts 90, what is the initial dosage? 30- b) What is the average amount of phenylbutazone in the calf's body for the time between 15 and 90 hours? D 20- 10- 0+ 0 40 80 120