Line n passes through the points (–1, 4) and (–1, –4). which is true of line n? line n is a vertical line with an undefined slope. line n is a vertical line with a slope of zero. line n is a horizontal line with an undefined slope. line n is a horizontal line with a slope of zero.

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)