Four Common Forms of Parabola

As one of the most important geometric shapes, the parabola has a number of different forms and, when used in combination with other geometric shapes, can create some interesting formations. The parabola comes in many different sizes and can be found anywhere in any given shape. Parabolic mirrors are also common. The parabola can be found in many other locations, most often seen in a football stadium. The forms of parabolas can be classified into four main categories based on their structure and shapes. These four parabola forms are unbounded, bounded parabola, bi-convex parabola, and ellipse parabola.

Parabola

The term “parabola” comes from the Greek word “to throw or hurl something at a target.” If one throws a ball, it is said to be ‘in a parabola.’ The shape of the curve generated by such an ‘arrow’ depends on the angle at which the ball is thrown. Parabolic arcs are often used in place of circles to represent motion.

An object is thrown upwards following a parabolic trajectory called a parabola. The ball thrown from a planet’s surface to reflect the planet’s surface provides an example of the parabolic curve.

The parabola has been studied in mathematics and engineering for centuries, especially in areas such as optics, tractrix, and celestial mechanics. These areas gave rise to many mathematical terms which are still used today.

Key Features of a Parabola

• A parabola is defined as the graph of

“y” = “x”–”a,” where a is a fixed constant and x, y are real numbers.

• A parabola can be defined as the set of points equidistant from a given point concerning a given direction.
• When we pass two lines, called directrices, through a fixed point, as shown above, a unique ellipse is obtained. If these two lines are identical, then this ellipse becomes a parabola.
• The sum of the squares of the distances from the directrices to the fixed point is constant, so this sum is also constant. Hence, a parabola can be defined as all points equidistant from a given point concerning a given direction.
• Similarly, a parabola can be defined as the set of points on a circle equidistant from that circle’s center.
• A parabola intercepts every point on its directrix and forms a conic section.
• The sum of the distances from any point on the parabola to its focus and directrix is a constant that depends only on the shape and position of the parabola. This property defines the parabola uniquely since a conic section must pass through its focus, pass through its directrix, and have this property.
• A parabola can be defined as an ellipse with four equal focus points (called foci).
• When we draw a line through the foot of a parabola and then extend this lineup, we obtain another parabola.

Characteristics of Parabolas

• A parabola is a very symmetric curve concerning both reflection and rotation. Any reflective point or axis is also a rotational axis. The symmetry of the parabola is due to its property as a conic section, which makes it an ellipse, hyperbola, or circle.
• A parabola has a maximum or minimum value on the directrix and at least one maximum or minimum value at infinity.
• A parabola is a smooth curve, which means it is not made up of straight-line segments, like the graph of a quadratic function. If we try to make a straight line segment between any two points on a parabola by making them closer together, we cannot do it without leaving the parabola. This does not hold for other curves such as cubic graphs.

• The measure of the slope of the tangent to a parabola is equal to the distance from that point to the focus, divided by the distance from that point to the directrix. This follows from measurement of angle and length, similar to tan(2A) = 2sin(A)/x.

The Forms of Parabolas

The forms of parabolas are divided into four most common types:

• The first type is known as an open or unbounded parabola. It has a vertex of symmetry located at the center of a circle and extends indefinitely from it. 
• The second type, the closed or bounded parabola, is bounded by two concentric circles with two branches having equal lengths from the focus point. 
• The third type is the bi-convex parabola which has a vertex at the bottom of a segment connecting two points on a circle. 
• The fourth type is also known as an ellipse and is specified from two perpendicular lines that intersect at the focus point of a given parabola.

Conclusion

The article makes some generalizations about equidistant points on a parabola. In addition to these parabolas, certain parabolas may have a unique name, depending on how they are connected. A parabola with a point of intersection located at its vertex may be called a tangential parabola. A parallelogram with the same base and opposite sides parallel to the axes of symmetry may be referred to as a rectangular parabola. The figure formed by connecting the midpoints of a parabola’s two branches that pass through the focus point is called an axis of symmetry.