Which expression represents the area of the base of the cone? A cone with diameter 12 inches, height 8 inches, and slant height 10 inches. B = pi r squared (pi) (5 squared) (pi) (6 squared) (pi) (10 squared) (pi) (12 squared)

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)