Answer will rate and give if 2 people anwser it

Aman steps out of a plane at a height of 4,000m above the ground falls 2,000m very quickly and then opens his parachute and slowly falls the remaining 2000m to the ground what height above the ground would be the best choice for a reference point

In which direction does the left side of the graph of this function point? f(x) = 3x3 - x2 + 4x - 2

Tell whether the two rates form a proportion