The graph of $f(x) = x^3$ is given in the first Figure in this problem.

You can describe this function to WeBWorK by entering x**3 here: . (Go ahead, try it right now.)
Consider the function whose graph is given in this Figure:

Let's call that function $g(x) =$ . (Enter an algebraic expression.)
Hint: Ask what happens to the point where the graph of $f$ is momentarily horizontal. (This is called a saddle point of $f$.)