If you don't know it, don't answer it. Describe the vertical line test.
A: If a vertical line can be drawn anywhere in the graph the line will pass through the graph in more than one spot.
B: If a vertical line can be drawn anywhere in the graph the line will pass through the graph in only one spot.
C: If the graph is a vertical line, it is a function.
D: If the graph is not a vertical line, it is a function.

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)