Yo necesito saber sobre una pregunta del calendario matematico de 5 de primaria la pregunta que yo nesecito saber es lunes 16-09-19

What is this inequality notation? t is less then or equal to 2

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?

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)