March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is an attractive and versatile geometric shape which managed to captured the attention of mathematicians and scientists for hundreds of years. Its unique properties and simple yet exquisite equation makes it a powerful tool for molding a wide range of real-life phenomena. From the flight path of a projectile to the shape of a satellite dish, the parabola plays a crucial role in various domains, including architecture, engineering, physics, and mathematics.

A parabola is a kind of U-shaped section, that is a curve made by intersecting a cone over a plane. The parabola is determined with a quadratic equation, and its characteristics, for example the vertex, focus, directrix, and symmetry, provide precious insights into its action and functions. By understanding the parabola formula and its properties, we could obtain a deeper admiration for this essential geometric shape and its many usages.

In this article, we will examine the parabola in detail, from its properties and equation to instances of how it could be applied in many domains. Whether you're a student, a working professional, or merely curious about the parabola, this blog will provide a complete summary of this fascinating and important concept.

Parabola Equation

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

y = ax^2 + bx + c

here a, b, and c are constants that establish the shape, size, and position of the parabola. The value of a determines whether the parabola opens up or down. If a is greater than 0, the parabola opens upward, and if a lower than 0, the parabola opens downward. The vertex of the parabola is situated 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 spot where the curve changes direction. It is also the point where the axis of symmetry intercepts the parabola. The axis of symmetry is a line that goes through the vertex and divides the parabola into two equal portions.


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


The directrix is a line which is perpendicular to the axis of symmetry and located 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 in relation to its axis of symmetry. Which states that if we consider any point on one side of the axis of symmetry across the axis, we get a corresponding point on the other side of the axis.


The parabola crosses the x-axis at two points, specified 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 are required to find 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 positioned at the point (2, -1). The axis of symmetry is the line x = 2.

Subsequently, we can find the x-intercepts by assuming y = 0 and solving for x. We obtain:

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 draw the graph of the parabola by plotting the vertex, the x-intercepts, and the y-intercept, and portraying the curve of the parabola between them.

Example 2: Using a Parabola in Physics

The parabolic curve of an object's trajectory is a general example of the parabola in physics. When an object is launched or thrown into the air, it follows a course that is represented 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, along with the vertex at the coordinate (0, 0) and the axis of symmetry parallel to the ground. The focus of the parabola depicts the landing point of the projectile, and the directrix depicts the height above the ground where the projectile would strike if it weren’t influenced by gravity.


In conclusion, the parabola formula and its properties perform an essential function in many domains of study, consisting of mathematics, engineering, architecture, and physics. By understanding the equation of a parabola, its characteristics such as the vertex, focus, directrix, and symmetry, and its several applications, we could gain a detailed understanding of how parabolas function and how they can be applied to model real-world phenomena.

Whether you're a student struggling to understand the concepts of the parabola or a professional want to apply parabolic equations to real-life problems, it's crucial to have a strong groundwork in this elementary topic.

This's where Grade Potential Tutoring comes in. Our expert instructors are available online or in-person to offer individualized and productive tutoring services to help you master the parabola and other math theories. Call us today to plan a tutoring session and take your mathematical abilities to the next level.