Consider a circle that has a circumference of 28π centimeters.

PART A
What is the area, in cm^2, of this circle?

Part B
What would be the measure of the radius, in cm, of a circle with an area 20% greater than the circle in Part A?

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)