When a certain prescription drug is taken orally by an adult, the amount of the drug (in mg/L) in the bloodstream at t hours is given by the function y=f (t)

1. What is the concentration of the drug in the bloodstream at t = 8 hours?

2. During what time interval is the drug level in the bloodstream increasing? Decreasing?

1. y = f (8)

2. So for t which f' (t) > 0, the drug level in the bloodstream is increasing. And for t which f' (t) < 0, it is decreasing.

Step-by-step explanation:

The concentration of the drug in the bloodstream at t hours is:

y = f (t)

1. What is the concentration of the drug in the bloodstream at t = 8 hours?

At t hours, y = f (t)

So at 8 hours, y = f (8)

2. During what time interval is the drug level in the bloodstream increasing? Decreasing?

A function f (t) is increasing when

f' (t) > 0

And is decreasing when

f' (t) < 0

So for t which f' (t) > 0, the drug level in the bloodstream is increasing. And for t which f' (t) < 0, it is decreasing.