March 16, 2023

Equation, Properties, Examples | Parabola Formula

The parabola is an appealing and multifaceted geometric shape which managed to captured the attention of mathematicians and scientists for ages. Its unique properties and simple yet elegant equation makes it a strong tool for modeling a wide assortment of real-world phenomena. From the path of a projectile to the shape of a satellite dish, the parabola plays an essential role in numerous domains, consisting of architecture, engineering, physics, and mathematics.

A parabola is a kind of conic portion, that is a curve formed by overlapping a cone over a plane. The parabola is specified by a quadratic equation, and its characteristics, for example the vertex, focus, directrix, and symmetry, give important insights into its behavior and uses. By understanding the parabola formula and its characteristics, we can gain a deeper admiration for this essential geometric shape and its various applications.

In this article, we will explore the parabola in depth, from its equation and properties to instances of how it could be utilized in multiple fields. Whether you're a student, a working professional, or just curious regarding the parabola, this article will offer a complete overview of this fascinating and crucial concept.

Parabola Equation

The parabola is stated 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 determines whether the parabola opens upward or downward. If a > 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 location where the curve changes direction. It is further the point where the axis of symmetry intersects the parabola. The axis of symmetry is a line that moves across the vertex and divides the parabola within two proportionate halves.


The focus of the parabola is the point] on the axis of symmetry that is equidistant from the directrix and vertex. 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 situated at a length of 1/4a units from the vertex. Every points on the parabola are equal distance from the focus and the directrix.


The parabola is symmetric with respect to its axis of symmetry. Which states that if we select any given point on one side of the axis of symmetry throughout the axis, we attain a corresponding point on the other side of the axis.


The parabola crosses 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 point (0, c).

Examples of Parabolas

Here are some primary examples of Parabolas:

Example 1: Graphing a Parabola

Let's graph the parabola y = x^2 - 4x + 3. First, we need to find the vertex, axis of symmetry, and intercepts. We can use 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 located at the point (2, -1). The axis of symmetry is the line x = 2.

Later, we can figure 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.

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

Utilizing this knowledge, we can draw the graph of the parabola by plotting the vertex, the x-intercepts, and the y-intercept, and drawing the curve of the parabola within them.

Example 2: Use of Parabola in Physics

The parabolic curve of a projectile's trajectory is a general example of the parabola in physics. When a projectile is launched or thrown upward, it follows a path 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 represented by:

y = xtan(θ) - (gx^2) / (2v^2cos^2(θ))

where g is the acceleration as a result 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 parallel to the ground. The focus of the parabola represents the landing spot of the object, and the directrix portrays the height above the ground where the projectile would hit if it were not impacted by gravity.


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

Whether you're a student struggling to comprehend the concepts of the parabola or a working professional looking to use parabolic equations to real-world problems, it's important to have a strong groundwork in this elementary topic.

This's where Grade Potential Tutoring enters. Our expert tutors are accessible online or face-to-face to provide personalized and effective tutoring services to help you master the parabola and other mathematical concepts. Call us today to plan a tutoring session and take your mathematical skills to the next stage.