Can someone me understand this problem and you

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)

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

Select the correct answer what is the most direct use of a compass in geometric constructions? a. to draw congruent angles b. to draw arcs of a given size c. to draw perpendicular lines d. to draw straight lines reset next next