Answer
a. No, $w(2)$ cannot be negative because the lowest number of words typed in a minute is 0.
b. wpm (words per minute)
c. $\frac{dw}{dt}|_{t=2}$ can be negative if the number of words typed per minute is decreasing at week 2.
Work Step by Step
a. We know that $w(2)$ cannot be negative because the lowest number of words typed in a minute is 0 and it cannot be less.
b. We can see from the question that the units are wpm (words per minute).
c. We can see that $\frac{dw}{dt}|_{t=2}$ can be negative if the number of words typed per minute is decreasing at week 2 because it can be less than before but still not less than 0.
