March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is an attractive and multifaceted geometric shape that has captured the attention of scientists and mathematicians for hundreds of years. Its unique properties and unsophisticated yet elegant equation makes it a powerful equipment for shaping a wide range of real-life phenomena. From the flight path of a projectile to the shape of a satellite dish, the parabola performs an important role in numerous domains, involving engineering, physics, architecture, and math.

A parabola is a kind of U-shaped section, which is a curve formed by overlapping a cone over a plane. The parabola is determined by a quadratic equation, and its characteristics, for instance the directrix, vertex, focus, and symmetry, provide valuable understanding into its action and uses. By grasping the parabola formula and its characteristics, we could gain a detailed recognition for this essential geometric shape and its many applications.

In this blog, we wish to study the parabola in depth, from its equation and properties to examples of how it could be used in many fields. Whether you're a student, a professional, or simply interested about the parabola, this article will offer a complete overview of this intriguing and crucial concept.

Parabola Equation

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

y = ax^2 + bx + c

at this point a, b, and c are constants which determine the size, shape, and position of the parabola. The value of a determines whether 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 spot 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 which passes across the vertex and splits the parabola within two equal halves.


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 length of 1/4a units from the vertex.


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. All points on the parabola are equal distance from the directrix and the focus.


The parabola is symmetric with respect to its axis of symmetry. This states that if we reflect any given point on one side of the axis of symmetry throughout the axis, we obtain 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 coordinated (0, c).

Examples of Parabolas

Here are few basic examples of Parabolas:

Example 1: Graphing a Parabola

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

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

to figure out the vertex. Placing in the values a = 1, b = -4, and c = 3, we get:

vertex = (2, -1)

So the vertex is positioned 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 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.

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

Using this knowledge, we can draw the graph of the parabola through plotting the vertex, the x-intercepts, and the y-intercept, and portraying the curve of the parabola within them.

Example 2: Using a Parabola in Physics

The parabolic shape of a projectile's trajectory is a common applications of the parabola in physics. While an object is launched or thrown into the air, it follows a course which is represented 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 represented 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 traveled by the object, respectively.

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


In summary, the parabola formula and its properties play an essential role in several fields of study, including math, engineering, architecture, and physics. By knowing the equation of a parabola, its characteristics for instance the directrix, vertex, and focus, and symmetry, and its several applications, we could gain a deeper comprehension of how parabolas function and how they can be utilized to model real-life phenomena.

Whether you're a student struggling to grasp the theories of the parabola or a working professional want to use parabolic equations to real-world challenges, it's crucial to possess a solid groundwork in this basic topic.

That's where Grade Potential Tutoring walks in. Our expert tutors are accessible online or in-person to offer customized and effective tutoring services to guide you conquer the parabola and other mathematical concepts. Contact us today to schedule a tutoring session and take your mathematical skills to the next level.