20. mark wants to create several passwords for several accounts. ench password is 9 characters consisting of arrangements of the 4 letters of his name followed by 5 digits from his birth date 8 / (21/73) . how many passwords can he create?

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)