The dashed line going through the maximum or minimum point is the quadratic's axis of symmetry. The axis of symmetry divides the quadratic into equal halves.[br][br]The real number roots of a quadratic are either one or two points on the x-axis. The distance between the roots is divided in half by the axis of symmetry. [br][br]The [math]x[/math] value of the min or max is [math]-\frac{b}{2a}[/math].[br]The [math]y[/math] value of the min or max is [math]f\left(-\frac{b}{2a}\right)[/math].[br]The min or max is the point [math]\left(-\frac{b}{2a},f\left(-\frac{b}{2a}\right)\right)[/math].