How long is crosspiece ab? (give answer to tenths accuracy.)

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)

Marion has a bicycle that she is planning to take for a ride. the rim of the rear wheel lies 41 cm from the center of the wheel. the tire itself has a thickness of 3 cm. in order for marion to ride her bicycle 96,712 cm approximately how many rotations will the rear wheel make?

Ethan is proving that the slope between any two points on a straight line is the same. he has already proved that triangles 1 and 2 are similar. drag statements and reasons to complete the proof.