Im a little confused can I get some help I dont understand this part.

Cameron made 1 loaf of bread. his family ate 4/6 of the loaf of bread. how much of the loaf of bread remains? /

Is this a polynomial function? i need to know asap

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)