Exploring Quadratic Equations

[math]y = a(x-h)^2 +k[/math] is the vertex form of a quadratic equation. The vertex is the point [math](h, k)[/math] on the quadratic. The vertex is the minimum or maximum of the quadratic. [math]y = ax^2 + bx +c[/math] is the standard form of a quadratic equation. Move slider [math]a[/math]. See the width of the quadratic change. See the direction of the quadratic change when [math]a[/math] is a negative number. Positive [math]a[/math] give the quadratic a minimum point. Negative [math]a[/math] give the quadratic a maximum point. Move slider [math]h[/math]. See the horizontal position of the quadratic change. Positive [math]h[/math] values keep the minimum or maximum of the quadratic to the right of the [math]y[/math]-axis. Negative [math]h[/math] values keep the minimum or maximum of the quadratic to the left of the [math]y[/math]-axis. Move slider [math]k[/math]. See the vertical position of the quadratic change. Positive [math]k[/math] values keep the minimum or maximum of the quadratic above the [math]x[/math]-axis. Negative [math]k[/math] values keep the minimum or maximum of the quadratic above the [math]x[/math]-axis.

Locating the Real Roots of a Quadratic

The real roots of a quadratic are the [math]x[/math] values of the points where the quadratic intersects the [math]x[/math]-axis.

Maximum or Minimum of a Quadratic

[math]y=ax^2 +bx +c[/math] is the standard form of a quadratic equation. Move quadratic [math]b[/math]. Quadratic [math]b[/math] has a maximum point since its [math]ax^2[/math] term in negative. Move quadratic [math]c[/math]. Quadratic [math]c[/math] has a minimum point since its [math]ax^2[/math] term in positive. The dashed line going through the maximum or minimum point is the quadratic's axis of symmetry. The axis of symmetry divided the quadratic into equal halves.

Trajectory of an Object Represented by a Quadratic Equation

A quadratic equation can represent the trajectory of an object thrown in the air. A trajectory is the path of an object while it is in the air, ending when it hits the ground or intended target. Point A gives the starting height of the object the millisecond it is released. The [math]y[/math] value of point A is the starting height. Point B is the vertex of the quadratic. Point B gives the maximum height of the object in the air. The [math]y[/math] value of point B is the maximum height. Point C is one of the roots of the quadratic. Point C gives the maximum horizontal distance of the object. The [math]x[/math] value of point C is the total distance the object was thrown. When point C is on the [math]x[/math]-axis, it is considered ground level. Move sliders [math]a[/math], [math]b[/math] or [math]c[/math]. Slider [math]a[/math] is the coefficient in the term [math]ax^2[/math]. Slider [math]b[/math] is the coefficient in the term [math]bx[/math]. Slider [math]c[/math] is the constant term (also the coefficient in the term [math]cx^0[/math]).

Information