Answer
The shape of the parabola widens as the value of $a$ gets close to zero.
The shape of the parabola becomes narrower as the value of $a$ gets large.
Work Step by Step
As the value of the coefficient $a$ approaches zero, the parabola shape becomes wider and approaches a horizontal straight line.
As the value of the coefficient $a$ becomes larger, the parabola shape becomes narrower and approaches a vertical straight line.
