Can u help me with my math

An objects motion is described by the equation d= 4sin (pi t) what will the height of the object be at 1.75 seconds?

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)

On a piece of paper, graph y< x-1. then determine which answer choicematches the graph you drew.13. z3. 2(3.290-1)