Ik this is like weird but..Can someone that’s sum what smart ft me and please help will my work ‍♀️

In a graph with several intervals o data how does a constant interval appear? what type of scenario produces a constant interval?

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)

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6