March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is a fascinating and versatile geometric shape that managed to drew the attention of mathematicians and scientists for hundreds of years. Its unusual properties and unsophisticated yet exquisite equation makes it a strong equipment for shaping a broad assortment of real-world phenomena. From the path of a projectile to the shape of a satellite dish, the parabola performs a crucial role in various fields, involving architecture, engineering, physics, and mathematics.

A parabola is a kind of U-shaped section, which is a curve created by overlapping a cone over a plane. The parabola is defined by a quadratic equation, and its features, for example the directrix, vertex, focus, and symmetry, provide precious insights into its behavior and uses. By grasping the parabola formula and its characteristics, we could gain a detailed recognition for this fundamental geometric shape and its multiple usages.

In this article, we wish to examine the parabola in detail, from its equation and properties to instances of how it could be utilized in many domains. Even if you're a learner, a working professional, or simply interested about the parabola, this article will provide a complete overview of this fascinating and essential concept.

Parabola Equation

The parabola is defined with a quadratic equation of the form:

y = ax^2 + bx + c

at this point a, b, and c are constants that establish the shape, size, and position of the parabola. The value of a decides if the parabola opens up or down. If a > 0, the parabola opens upward, and if a less than 0, the parabola opens downward. The vertex of the parabola is located at the point (-b/2a, c - b^2/4a).

Properties of the Parabola

Here are the properties of Parabola:


The vertex of the parabola is the point where the curve changes direction. It is further the point where the axis of symmetry intercepts the parabola. The axis of symmetry is a line that goes across the vertex and divides the parabola into two symmetrical parts.


The focus of the parabola is a point] on the axis of symmetry that is equidistant from the vertex and the directrix. The directrix is a line that is perpendicular to the axis of symmetry and placed at a length of 1/4a units from the vertex.


The directrix is a line which is perpendicular to the axis of symmetry and placed at a length of 1/4a units from the vertex. Every points on the parabola are equidistant from the directrix and the focus.


The parabola is symmetric with regard to its axis of symmetry. This defines that if we select any location on one side of the axis of symmetry across the axis, we attain a corresponding point on the other side of the axis.


The parabola crosses the x-axis at two points, provided by the formula:

x = (-b ± sqrt(b^2 - 4ac)) / 2a

The parabola intersects the y-axis at the coordinated (0, c).

Examples of Parabolas

Here are number of basic examples of Parabolas:

Example 1: Graphing a Parabola

Let's graph the parabola y = x^2 - 4x + 3. Foremost, we need to calculate the vertex, axis of symmetry, and intercepts. We can utilize the formula:

vertex = (-b/2a, c - b^2/4a)

to find the vertex. Plugging in the values a = 1, b = -4, and c = 3, we obtain:

vertex = (2, -1)

So the vertex is situated at the point (2, -1). The axis of symmetry is the line x = 2.

Subsequently, we can find the x-intercepts by taking y = 0 and calculating for x. We get:

x^2 - 4x + 3 = 0

(x - 3)(x - 1) = 0

Accordingly the parabola intersects the x-axis at x = 1 and x = 3.

Finally, the y-intercept is the coordinates (0, c) = (0, 3).

Utilizing this information, we can plot the graph of the parabola by plotting the vertex, the x-intercepts, and the y-intercept, and drawing the curve of the parabola between them.

Example 2: Use of Parabola in Physics

The parabolic curve of a projectile's trajectory is a general example of the parabola in physics. When a projectile is thrown or launched into the air, it follows a path that is described with a parabolic equation. The equation for the course of a projectile launched from the ground at an angle θ through an initial velocity v is given by:

y = xtan(θ) - (gx^2) / (2v^2cos^2(θ))

where g is the acceleration due to gravity, and x and y are the horizontal and vertical length traveled by the projectile, respectively.

The trajectory of the object is a parabolic curve, with the vertex at the coordinate (0, 0) and the axis of symmetry corresponding to the ground. The focus of the parabola represents the landing point of the object, and the directrix portrays the height above the floor where the object would strike if it weren’t affected by gravity.


In summary, the parabola formula and its properties play an important role in several domains of study, involving arithmetics, architecture, physics, and engineering. By knowing the equation of a parabola, its characteristics such as the vertex, focus, directrix, and symmetry, and its several utilizations, we can obtain a detailed understanding of how parabolas work and how they could be applied to model real-world scenario.

Whether you're a learner struggling to comprehend the theories of the parabola or a working professional looking to use parabolic equations to real-world problems, it's crucial to have a firm foundation in this elementary topic.

That's where Grade Potential Tutoring comes in. Our experienced teachers are available online or in-person to offer personalized and productive tutoring services to guide you conquer the parabola and other mathematical concepts. Call us today to schedule a tutoring session and take your mathematical abilities to the next level.