Please ANSWER THE ANSWER HAS TO BE A INTEGER OR A DECIMAL.

Really need on these. i have no idea what to do

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)

Two triangles can be formed with the given information. use the law of sines to solve the triangles. b = 49°, a = 16, b = 14