December 30, 2022

Distance Between Two Points - Formula, Derivation, Examples

The concept of length is crucial in both math and everyday life. From straightforward calculating the extent of a line to working out the quickest route among two extremities, understanding the distance among two points is crucial.


In this blog, we will explore the formula for distance between two extremities, work on some examples, and talk about real-life uses of this formula.

The Formula for Distance Within Two Points

The distance within two locations, often signified as d, is the extent of the line segment connecting the two extremities.


In math, this can be portrayed by drawing a right triangle and utilizing the Pythagorean theorem. According to Pythagorean theorem, the square of the distance of the extensive side (the hypotenuse) is equal to the total of the squares of the distances of the two other sides.


The formula for the Pythagorean theorem is a2 + b2 = c2. As a result, √c2 will as same as the distance, d.


In the case of working out the distance between two points, we can portray the extremities as coordinates on a coordinate plane. Let's say we possess point A with coordinates (x1, y1) and point B at (x2, y2).


We could further employ the Pythagorean theorem to derive the ensuing formula for distance:

d = √((x2 - x1)2 + (y2 - y1)2)


In this formula, (x2 - x1) depicts the length on the x-axis, and (y2 - y1) portrays the length along y-axis, forming a right angle. By taking the square root of the sum of their squares, we get the length within the two points.


Here is a graphical depiction:


Instances of Applications of the Distance Formula

Once we possess the formula for distance, let's look at some examples of how it can be used.

Calculating the Length Among the Two Locations on a Coordinate Plane

Imagine we have two extremities on a coordinate plane, A with coordinates (3, 4) and B with coordinates (6, 8). We will utilize the distance formula to find the distance between these two points as ensues:


d = √((6 - 3)2+ (8 - 4)2)

d = √(32 + 42)

d = √(9 + 16)

d = √(25)

d = 5


Therefore, the distance between points A and B is 5 units.

Calculating the Distance Among Two Locations on a Map

In addition to figuring out the length on a coordinate plane, we could also utilize the distance formula to calculate distances within two locations on a map. For instance, suppose we have a map of a city with a scale of 1 inch = 10 miles.


To work out the distance between two points on the map, such as the airport and the city hall, we can simply measure the length among the two points utilizing a ruler and convert the measurement to miles using the map's scale.


When we measure the distance within these two locations on the map, we find it is 2 inches. We convert this to miles using the map's scale and find out that the real length between the city hall and the airport is 20 miles.

Calculating the Length Among Two Points in Three-Dimensional Space

In addition to calculating lengths in two dimensions, we could further use the distance formula to work out the distance among two points in a three-dimensional space. For instance, assume we possess two locations, A and B, in a three-dimensional space, with coordinates (x1, y1, z1) and (x2, y2, z2), individually.


We will utilize the distance formula to find the distance between these two points as ensuing:

d = √((x2 - x1)2 + (y2 - y1)2 + (z2 - z1)2)


Utilizing this formula, we can calculate the distance within any two locations in three-dimensional space. For example, if we have two locations A and B with coordinates (1, 2, 3) and (4, 5, 6), individually, we could figure out the distance between them as ensues:


d = √((4 - 1)2 + (5 - 2)2 + (6 - 3)2)

d = √(32 + 32 + 32)

d = √(9 + 9 + 9)

d = √(27)

d = 3.16227766


Therefore, the distance within locations A and B is roughly 3.16 units.

Applications of the Distance Formula

Now that we have looked at some examples of utilizing the distance formula, let's examine few of its applications in math and other fields.

Measuring Length in Geometry

In geometry, the distance formula is utilized to calculate the distance of line segments and the sides of triangles. For instance, in a triangle with vertices at points A, B, and C, we use the distance formula to figure out the distances of the sides AB, BC, and AC. These distances can be utilized to calculate other properties of the triangle, such as its area, perimeter and its interior angles.

Solving Problems in Physics

The distance formula is further employed in physics to figure out questions concerning acceleration, speed and distance. For example, if we recognize the initial location and velocity of an object, as well as the time it takes for the object to move a certain distance, we could use the distance formula to figure out the object's final position and speed.

Analyzing Data in Statistics

In statistics, the distance formula is usually utilized to calculate the distances within data points in a dataset. This is useful for clustering algorithms, that group data points that are close to each other, and for dimensionality reduction techniques, which depicts high-dimensional data in a lower-dimensional space.

Go the Distance with Grade Potential

The distance formula is an essential theory in mathematics that enables us to calculate the between two points on a plane or in a three-dimensional space. By utilizing the Pythagorean theorem, we could derive the distance formula and implement it to a variety of scenarios, from calculating length on a coordinate plane to analyzing data in statistics.


Understanding the distance formula and its applications are essential for everyone fascinated in mathematics and its applications in other fields. If you're struggling regarding the distance formula or any other mathematical concept, reach out to Grade Potential tutoring for customized guidance. Our expert teachers will help you conquer any mathematics topic, from algebra to calculus and furthermore.


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