If the graph of the function y = f(x) is a parabola, then the functions y and

If the graph of the function y = f(x) is a parabola, then the functions Δy and dy (of the independent variable Δx = dx) for f(x) at x = 0 are identical.
In Problem, discuss the validity of each statement. If the statement is always true, explain why. If not, give a counterexample.