As Freda gazes at the edge of the Grand Canyon, she decides to try to determine the height of the wall opposite her. Using an app on her phone, she determines that the top of the wall is at a 38° angle above her, while the bottom is at a 46° angle
below her, as shown in the diagram at right. If the base of the wall is 253 feet from the point on the ground directly below
Freda, determine the height of the wall opposite her.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 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)