As a pharmacist, you are responsible for knowing about medication dosage, and how long a dose stays in the patient's system. Let's look at an example of a common medication, called ibuprofen. When a patient takes a 400 mg dose of ibuprofen, it releases into the bloodstream at a certain rate, and then decreases over time. The function that models this concentration of medicine over time is complex and looks like this:
P(t) = 0.5t + 3.45t³ - 96.65t² + 347.7t, when 0 ≤t≤6 . In this function above, P(t) is the amount of medication (in mg) in the
blood stream at time t (in hours).
When put into a graphing software, it looks like this:

1) Why do we only need to look at the interval 0 ≤ t ≤ 6