Tammy has $640 in the bank. She is saving for a trip. She has 8 weeks before she leaves. The total cost of the trip is $1,200. Which number line represents all the possibilities for her weekly saving amount that give her at least the minimum amount of money for the trip?

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)