A runner completed a 26.2-mile marathon in 210 minutes. a. Estimate the unit rate, in miles per minute. Round your answer to the nearest hundredth of a mile. The unit rate is about mile per minute. b. Estimate the unit rate, in minutes per mile. Round your answer to the nearest tenth of a minute. The unit rate is about minutes per mile.

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)