‏Which statement about internal customers is true ? a ) Internal customers rely on someone else at the same company to help them do their job . b ) Internal customers are more important than external customers . c ) Each individual should have no more than five internal customers . d ) Internal customers can be guests , customers , or clients .

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)