Joshua's mail truck travels 14 miles every day he works and is not used at all on days he does not work. At the
end of his 100th day of work the mail truck shows a
mileage of 76,762. Model Joshua's truck mileage as a
function of the number of days he has worked. When
will he reach 100,000 miles?

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)