1. On a graph of a function, what does a perfectly horizontal line segment indicate?
2. The speed of a train is monitored. It travels at a steady 65 mph from hour 2 to hour 4 of its journey. The speed function is constant on the interval $2 \leq x \leq$ ___.
3. A patient's temperature was stable at $99.5^\circ F$ from 8 AM to 11 AM. If $x$ represents the hours after midnight, on which interval was the temperature function constant?
4. A graph shows the value of a collectible toy over several years. The value was constant at 75 dollars from year 4 to year 9. For any year $x$ in the interval $4 \leq x \leq 9$, the value was ___ dollars.
5. True or False: If a function is constant on an interval, its graph over that interval is a straight line that is not horizontal.
6. On what interval is the function $f(x) = (x - 3)^2$ increasing? Use interval notation. The answer is ___.
7. A function is described as increasing on an interval. What does this mean about its graph on that interval?
8. On what interval is the function $g(x) = |x + 5|$ decreasing? Use interval notation. The answer is ___.
9. On which interval is the function $h(x) = 4x - 7$ increasing?
10. Determine the interval on which the function $f(x) = -x^2 + 1$ is increasing. Use interval notation. The answer is ___.