March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is a fascinating and multifaceted geometric shape that has captured the attention of scientists and mathematicians for centuries. Its unusual properties and simple yet exquisite equation makes it a powerful tool for modeling a broad range of real-world phenomena. From the path of a projectile to the shape of a satellite dish, the parabola performs an essential role in various domains, involving architecture, engineering, physics, and mathematics.

A parabola is a kind of U-shaped portion, that is a curve made by overlapping a cone over a plane. The parabola is determined by a quadratic equation, and its features, for example the vertex, focus, directrix, and symmetry, give valuable insights into its behavior and uses. By understanding the parabola formula and its features, we can gain a detailed appreciation for this essential geometric shape and its multiple usages.

In this blog article, we wish to study the parabola in depth, from its properties and equation to examples of how it can be applied in multiple fields. Even if you're a learner, a working professional, or merely curious about the parabola, this blog will give a complete overview of this fascinating and crucial concept.

Parabola Equation

The parabola is stated by a quadratic equation of the form:

y = ax^2 + bx + c

here a, b, and c are constants that determine the size, shape, and position of the parabola. The value of a controls if the parabola opens up or down. If a is more than 0, the parabola opens upward, and if a < 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 shifts direction. It is further the point where the axis of symmetry intercepts the parabola. The axis of symmetry is a line that passes through the vertex and divides the parabola within two proportionate halves.


The focus of the parabola is the point] on the axis of symmetry which is equidistant from the vertex and the directrix. The directrix is a line that is perpendicular to the axis of symmetry and situated 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. All points on the parabola are equidistant from the directrix and the focus.


The parabola is symmetric in relation to its axis of symmetry. This means that if we reflect any point on one side of the axis of symmetry throughout the axis, we get a corresponding point on the opposite side of the axis.


The parabola crosses 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 coordinated (0, c).

Examples of Parabolas

Here are few simple examples of Parabolas:

Example 1: Graphing a Parabola

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

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

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

vertex = (2, -1)

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

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

x^2 - 4x + 3 = 0

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

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

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

Utilizing this knowledge, we could sketch the graph of the parabola through plotting the vertex, the x-intercepts, and the y-intercept, and portraying the curve of the parabola between them.

Example 2: Use of Parabola in Physics

The parabolic shape of a projectile's trajectory is a standard example of the parabola in physics. When an object is thrown or launched into the air, it follows a course which is represented with a parabolic equation. The equation for the course of a projectile thrown 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 as a result of gravity, and x and y are the horizontal and vertical distances covered by the projectile, respectively.

The trajectory of the projectile is a parabolic curve, along with the vertex at the point (0, 0) and the axis of symmetry corresponding to the ground. The focal point of the parabola portrays the landing spot of the object, and the directrix portrays the height above the floor where the projectile would hit if it were not affected by gravity.


Finally, the parabola formula and its properties play an essential function in several fields of study, consisting of arithmetics, engineering, architecture, and physics. By understanding the equation of a parabola, its characteristics such as the vertex, focus, directrix, and symmetry, and its numerous applications, we could gain a detailed understanding of how parabolas work and how they can be utilized to model real-world phenomena.

Whether you're a student struggling to understand the theories of the parabola or a working professional want to utilize parabolic equations to real-life challenges, it's crucial to have a firm foundation in this elementary topic.

This's where Grade Potential Tutoring enters. Our experienced tutors are available online or face-to-face to provide individualized and productive tutoring services to help you master the parabola and other mathematical concepts. Contact us today to schedule a tutoring session and take your math abilities to the next stage.