Store A sells silver wire for $8.00 per yard. Store B sells silver wire by the spool for $8.00 per spool. The cost of wire at either store can be modeled by the
function C(n) = 8n, where n is the number of yards for Store A and n is the
number of spools of wire for Store B.
The domain of C(n) = 8n is all real numbers.
For each store, drag all the additional restrictions needed on values of n for C(n)
to model each situation.

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)