Find the slope c(-8,-7) and d (13,-1

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)

How do you write something in scientific notation?

Taina went to the toy store and spent $21.05 on a board game, $2.75 on coloring books, and $13.22 on a model airplane. about how much money did taina spend in the toy store?