Can someone plz help I’m being timed hurry plzzz

What is the length of an with endpoints a 3,2 and b 8,14

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)

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?