Pine bluff middle school is having its annual spring fling dance, which will cost
$
4
0
0
$400dollar sign, 400. the student treasurer reported that the dance fund has
$
7
5
$75dollar sign, 75 left over from last year. each ticket to the dance costs
$
4
$4dollar sign, 4.

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)