Help please this is hard .

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)

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?

12 out of 30 people chose their favourite colour as blue caculate the angle you would use for blue on a pie chart