Pls help a

Acable car begins its trip by moving up a hill. as it moves up, it gains elevation at a constant rate of 50 feet/minute until it reaches the peak at 2,000 feet. then, as the car moves down to the hill’s base, its elevation drops at the same rate.

Which expression is equivalent to the expression shown?

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