December 30, 2022

Distance Between Two Points - Formula, Derivation, Examples

The theory of distance is vital in both math and everyday life. From simply measuring the length of a line to figuring out the quickest route among two extremities, comprehending the length within two points is crucial.


In this article, we will take a look at the formula for distance within two locations, review some examples, and discuss real-life utilizations of this formula.

The Formula for Distance Within Two Points

The length between two locations, frequently signified as d, is the extent of the line segment connecting the two points.


Mathematically, this could be portrayed by drawing a right triangle and utilizing the Pythagorean theorem. According to Pythagorean theorem, the square of the length of the longest side (the hypotenuse) is equivalent to the sum of the squares of the lengths of the two other sides.


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


In the circumstance of finding the length within two points, we could represent the points as coordinates on a coordinate plane. Let's assume we have point A with coordinates (x1, y1) and point B at (x2, y2).


We can thereafter utilize the Pythagorean theorem to derive the following formula for distance:

d = √((x2 - x1)2 + (y2 - y1)2)


In this formula, (x2 - x1) depicts the distance on the x-axis, and (y2 - y1) represents the distance along y-axis, forming a right angle. By considering the square root of the sum of their squares, we obtain the distance among the two points.


Here is a graphical illustration:


Instances of Applications of the Distance Formula

Considering we have the formula for distance, let's look at few instances of how it can be utilized.

Working out the Distance Among the Two Points on a Coordinate Plane

Assume we have two locations on a coordinate plane, A with coordinates (3, 4) and B with coordinates (6, 8). We will use the distance formula to find the distance within these two locations as follows:


d = √((6 - 3)2+ (8 - 4)2)

d = √(32 + 42)

d = √(9 + 16)

d = √(25)

d = 5


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

Calculating the Length Among Two Extremities on a Map

In addition to figuring out the distances on a coordinate plane, we could further utilize the distance formula to calculate distances between two locations on a map. For instance, assume we posses a map of a city with a scale of 1 inch = 10 miles.


To find the distance among two locations on the map, for instance the city hall and the airport, we could simply work out the distance within the two locations employing a ruler and convert the measurement to miles utilizing the map's scale.


When we calculate the distance between these two points on the map, we figure out it is 2 inches. We convert this to miles utilizing the map's scale and find that the actual length within the airport and the city hall is 20 miles.

Working out the Distance Within Two Locations in Three-Dimensional Space

In addition to finding lengths in two dimensions, we can also utilize the distance formula to calculate the distance among two points in a three-dimensional space. For example, assume we possess two points, A and B, in a three-dimensional space, with coordinates (x1, y1, z1) and (x2, y2, z2), respectively.


We will employ the distance formula to find the distance between these two points as follows:

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


Using this formula, we can identify the distance among 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 work out the length 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


Thus, the distance within points A and B is roughly 3.16 units.

Applications of the Distance Formula

Now once we have looked at some instances of using the distance formula, let's explore some of its uses in mathematics and other fields.

Measuring Distances in Geometry

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

Solving Problems in Physics

The distance formula is further used in physics to work out questions involving speed, distance and acceleration. For example, if we perceive the first position and velocity of an object, in addition to the time it requires for the object to transport a specific distance, we could utilize the distance formula to figure out the object's concluding location and speed.

Analyzing Data in Statistics

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

Go the Distance with Grade Potential

The distance formula is an essential idea in math that allows us to work out the distance between two points on a plane or in a three-dimensional space. By utilizing the Pythagorean theorem, we can derive the distance formula and implement it to a assortments of situations, from measuring length on a coordinate plane to analyzing data in statistics.


Understanding the distance formula and its utilizations are essential for anyone interested in mathematics and its uses in other areas. If you're struggling with the distance formula or any other math theories, Grade Potential tutoring for personalized guidance. Our expert teachers will help you master any mathematics topic, from algebra to calculus and beyond.


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