Dani experimented with a dollar bill and the copy machine a dollar bills length is 6.1 inches and width is 2.6 inches, she reduced the dollar bill so its length was 80% of its original size. What is the length of the copy of the dollar bill? please show how you figured it out :)

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)