The length of a rectangle is 3cm greater than its width. The perimeter is 24 cm. Find the dimensions of the rectangle a) 7.5cm, 10.5cm
b) 4.5cm, 7.5cm
c) 10.5cm, 13.5cm
d) 3 cm, 9 cm

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)