A random sample of dogs at different animal shelters in a city shows that 8 of
the 55 dogs are puppies. The city's animal shelters collectively house 1,540
dogs each year. About how many dogs in all of the city's animal shelters are
puppies?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)