Sean began jogging to live a healthier lifestyle. on his first run, he ran one-half mile. he increased his workouts by adding two miles a month to his run. he wrote the equation f(x)= 0.5 + 2x to model his progress. the variable x represents the number of

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)