March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is an appealing and multifaceted geometric shape that managed to captured the attention of scientists and mathematicians for hundreds of years. Its unique properties and unsophisticated yet exquisite equation makes it a powerful tool for shaping a broad array of real-life phenomena. From the trajectory of a projectile to the shape of a satellite dish, the parabola plays an important role in numerous domains, including engineering, physics, architecture, and mathematics.

A parabola is a kind of conic piece, which is a curve created by overlapping a cone through a plane. The parabola is determined with a quadratic equation, and its features, for instance the vertex, focus, directrix, and symmetry, offer important insights into its performance and uses. By grasping the parabola formula and its features, we can obtain a detailed admiration for this essential geometric shape and its many usages.

In this blog, we wish to examine the parabola in detail, from its equation and properties to examples of how it can be used in various domains. Even if you're a learner, a professional, or simply curious regarding the parabola, this article will provide a complete summary of this fascinating and important 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 determine the shape, size, and position of the parabola. The value of a controls whether 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 location where the curve switches 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 within two symmetrical portions.


The focus of the parabola is the point] on the axis of symmetry that is equal distance from the vertex and the directrix. The directrix is a line which is perpendicular to the axis of symmetry and located at a distance 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 with respect to its axis of symmetry. Which states that if we reflect any location on one side of the axis of symmetry across the axis, we get a corresponding point on the opposite side of the axis.


The parabola intersects 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 some basic examples of Parabolas:

Example 1: Graphing a Parabola

Let's graph the parabola y = x^2 - 4x + 3. Primarily, we have 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. Placing in the values a = 1, b = -4, and c = 3, we get:

vertex = (2, -1)

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

Subsequently, we can work out the x-intercepts by taking y = 0 and solving 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.

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

Using this knowledge, we could 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 common example of the parabola in physics. When an object is thrown or launched into the air, it follows a path that is described by a parabolic equation. The equation for the path of a projectile launched from the ground at an angle θ with an initial velocity v is provided by:

y = xtan(θ) - (gx^2) / (2v^2cos^2(θ))

here g is the acceleration due to gravity, and x and y are the horizontal and vertical length covered by the projectile, 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 represents the landing point of the projectile, and the directrix portrays the height above the floor where the projectile would strike if it were not influenced by gravity.


In summary, the parabola formula and its characteristics perform an essential role in several fields of study, involving mathematics, architecture, physics, and engineering. By knowing the equation of a parabola, its properties for example the directrix, vertex, and focus, and symmetry, and its several applications, we could obtain a detailed understanding of how parabolas work and how they can be utilized to model real-world scenario.

Whether you're a learner finding it challenging to grasp the concepts of the parabola or a professional looking to apply parabolic equations to real-world problems, it's essential to have a strong foundation in this basic topic.

This's where Grade Potential Tutoring comes in. Our adept tutors are available online or in-person to offer personalized and productive tutoring services to help you conquer the parabola and other math concepts. Contact us right now to schedule a tutoring session and take your math skills to the next level.