March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is an attractive and multifaceted geometric shape that managed to drew the attention of scientists and mathematicians for centuries. Its exceptional properties and plain yet elegant equation makes it a strong equipment for modeling a wide array of real-world phenomena. From the path of a projectile to the shape of a satellite dish, the parabola plays a crucial role in numerous fields, involving architecture, engineering, physics, and mathematics.

A parabola is a kind of conic piece, that is a curve formed by overlapping a cone over a plane. The parabola is determined by a quadratic equation, and its properties, for example the directrix, vertex, focus, and symmetry, offer important understanding into its action and applications. By grasping the parabola formula and its characteristics, we could gain a deeper appreciation for this fundamental geometric shape and its multiple uses.

In this article, we wish to study the parabola in detail, from its equation and properties to examples of in what way it could be used in multiple fields. Even if you're a student, a professional, or merely curious about the parabola, this blog will offer a complete summary of this intriguing and essential concept.

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 decide the size, shape, and position of the parabola. The value of a controls whether the parabola opens upward or downward. 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 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 switches direction. It is also the point where the axis of symmetry intersects the parabola. The axis of symmetry is a line that goes across the vertex and divides the parabola into two proportionate halves.


The focus of the parabola is the 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 that is perpendicular to the axis of symmetry and placed at a length of 1/4a units from the vertex. All points on the parabola are equal distance from the focus and the directrix.


The parabola is symmetric with regard to its axis of symmetry. Which states that if we consider any location on one side of the axis of symmetry across the axis, we obtain a corresponding point on the opposite side of the axis.


The parabola intersects the x-axis at two points, given 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. Primarily, 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 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.

Later, we can work out the x-intercepts by setting 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.

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

Utilizing this knowledge, 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 standard applications of the parabola in physics. While an object is thrown or launched upward, it follows a course that is described with a parabolic equation. The equation for the course of a projectile thrown from the ground at an angle θ through an initial velocity v is represented by:

y = xtan(θ) - (gx^2) / (2v^2cos^2(θ))

here g is the acceleration because of gravity, and x and y are the horizontal and vertical distances traveled by the projectile, respectively.

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


In conclusion, the parabola formula and its characteristics perform an essential role in many fields of study, consisting of mathematics, engineering, architecture, and physics. By understanding the equation of a parabola, its properties such as the focus, directrix, and vertex, and symmetry, and its numerous utilizations, we can obtain a deeper comprehension of how parabolas work and how they can be used to model real-life phenomena.

Whether you're a learner finding it challenging to understand the concepts of the parabola or a professional looking to use parabolic equations to real-life problems, it's crucial to have a solid groundwork in this fundamental topic.

This's where Grade Potential Tutoring enters. Our experienced teachers are accessible online or in-person to offer customized and effective tutoring services to guide you master the parabola and other mathematical theories. Connect with us today to plan a tutoring session and take your math abilities to the next level.