If x and y are positive integers with x + y < 40, what is the largest possible product?

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)

What is the value of the expression i 0 × i 1 × i 2 × i 3 × i 4? 1 –1 i –i

:)i need to know on which ones are corresponding, alternate interior, alternate exterior, or none of these.