How would you do this problem because i don't know how to do this

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

Given: m∠ adb = m∠cdb ad ≅ dc prove: m∠ bac = m∠bca lol

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)