March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is a fascinating and versatile geometric shape which managed to drew the attention of mathematicians and scientists for hundreds of years. Its exceptional properties and plain yet elegant equation makes it a powerful equipment for molding a broad array of real-life phenomena. From the trajectory of a projectile to the shape of a satellite dish, the parabola plays an essential role in many fields, consisting of physics, architecture, engineering, and mathematics.

A parabola is a type of U-shaped portion, which is a curve formed by overlapping a cone over a plane. The parabola is determined by a quadratic equation, and its characteristics, for example the directrix, vertex, focus, and symmetry, provide valuable understanding into its performance and functions. By understanding the parabola formula and its characteristics, we can gain a deeper appreciation for this essential geometric shape and its various applications.

In this blog, we will examine the parabola in detail, from its equation and properties to examples of how it could be used in multiple domains. Even if you're a student, a working professional, or simply curious regarding the parabola, this article will offer a complete overview of this interesting and crucial idea.

Parabola Equation

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

y = ax^2 + bx + c

where a, b, and c are constants which establish the shape, size, and position of the parabola. The value of a controls whether the parabola opens up or down. If a is greater than 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 spot where the curve changes direction. It is also the point where the axis of symmetry intersects the parabola. The axis of symmetry is a line which moves through the vertex and splits the parabola into two equal 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 which is perpendicular to the axis of symmetry and situated at a distance of 1/4a units from the vertex.


The directrix is a line that is perpendicular to the axis of symmetry and located at a distance of 1/4a units from the vertex. All 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 given point 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 point (0, c).

Examples of Parabolas

Here are some simple examples of Parabolas:

Example 1: Graphing a Parabola

Let's graph the parabola y = x^2 - 4x + 3. First, we are required to figure out the vertex, axis of symmetry, and intercepts. We can use the formula:

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

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

vertex = (2, -1)

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

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

x^2 - 4x + 3 = 0

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

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

Ultimately, the y-intercept is the point (0, c) = (0, 3).

Applying this information, we can sketch the graph of the parabola through plotting the vertex, the x-intercepts, and the y-intercept, and drawing the curve of the parabola within them.

Example 2: Application of Parabola in Physics

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

y = xtan(θ) - (gx^2) / (2v^2cos^2(θ))

where g is the acceleration because of gravity, and x and y are the horizontal and vertical length covered by the object, respectively.

The trajectory of the projectile 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 portrays the landing point of the object, and the directrix depicts the height above the ground where the projectile would hit if it weren’t impacted by gravity.


In summary, the parabola formula and its properties play a crucial function in many fields of study, consisting of arithmetics, engineering, architecture, and physics. By understanding the equation of a parabola, its characteristics for example the focus, directrix, and vertex, and symmetry, and its numerous utilizations, we could gain a deeper understanding of how parabolas work and how they could be applied to model real-life phenomena.

Whether you're a learner struggling to understand the theories of the parabola or a professional want to apply parabolic equations to real-life challenges, it's essential to possess a solid foundation in this elementary topic.

This's where Grade Potential Tutoring comes in. Our expert instructors are available online or face-to-face to offer individualized and productive tutoring services to guide you master the parabola and other math concepts. Connect with us right now to schedule a tutoring session and take your arithmetic skills to the next level.