Please help I’ve been stuck on this for over an hour. (1) Measure your triangle's sides to the nearest millimeter, and then (2) place the measurements in the ratios. Finally, (3) using a calculator turn your ratios into decimals to three decimal places.

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)