Mason answers a question correctly in a trivia game and now has 0 points. The question was worth 15 points. Mason uses a number line to represent the number of points he received for answering
the question correctly and the number of points he had before answering the question. Where
would the two points be located on the number line?

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)