Grade 10

Grade 10Coordinate Geometry


Distance Formula


The distance formula in coordinate geometry helps to calculate the distance between two points in the plane. Originating from the Pythagorean theorem, it serves as a fundamental tool in mathematics, especially in algebra and geometry.

Understanding the basics

First, consider two points on the Cartesian plane: point A ((x1, y1)) and point B ((x2, y2)). The distance formula enables us to calculate the length of the line segment connecting these two points.

Formula

The mathematical expression for the distance d between points A and B is given as:

D = √((x2 - x1)² + (y2 - y1)²)

This formula is derived from the Pythagorean Theorem, which states that in a right triangle, the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.

Visual representation

Imagine two points A and B on a 2D plane. Create a right-angled triangle by drawing horizontal and vertical lines through these points.

A (x1, y1) B (x2, y2)

Step-by-step calculation

Let us learn how to use the formula to find the distance between two points with coordinates.

Example 1

Find the distance between point A ((3, 4)) and point B ((7, 1)).

  1. Calculate the difference in the x-coordinates: x2 - x1 = 7 - 3 = 4.
  2. Calculate the difference in the y-coordinates: y2 - y1 = 1 - 4 = -3.
  3. Apply the distance formula:
    D = √((4)² + (-3)²)
    d = √(16 + 9)
    d = √25
    d = 5
            

The distance between two points is 5 units.

Example 2

Let's try another example with points C ((-2, 8)) and D ((4, -3)).

  1. Difference in x-coordinates: 4 - (-2) = 4 + 2 = 6.
  2. Difference in y-coordinate: -3 - 8 = -11.
  3. Distance calculation:
    D = √((6)² + (-11)²)
    D = √(36 + 121)
    d = √157
    d ≈ 12.53
            

The approximate distance between these points is 12.53 units.

Applying usage to the real world

The distance formula is not limited to pure mathematics. It is widely used in physics, navigation and other fields.

Physics

In physics, this formula is essential for dealing with vectors, motion problems, and spatial calculations. For example, determining the shortest path between two positions.

Navigation

In navigation and GPS technology, the distance formula helps calculate the straight-line distance ("as-is") between two geographic locations.

Practice problems

Now it's your turn. Try applying the distance formula to solve the following problems:

Problem 1

Calculate the distance between the points E ((5, 9)) and F ((-3, 6)).

Problem 2

Find the distance between point G ((0, 0)) and point H ((-6, 8)).

Solution

Solve these questions and check your answers:

Solution 1

For problem 1:

D = √((-3 - 5)² + (6 - 9)²)
D = √((-8)² + (-3)²)
D = √(64 + 9)
d = √73
d ≈ 8.54

The distance is approximately 8.54 units.

Solution 2

For problem 2:

D = √((-6 - 0)² + (8 - 0)²)
D = √((6)² + (8)²)
D = √(36 + 64)
d = √100
d = 10

The distance is exactly 10 units.

Conclusion

The distance formula is an important mathematical tool that simplifies calculating the distance between two points in a 2D plane. Its applications extend beyond mathematics into a variety of scientific and real-world contexts, underpinning navigation systems, physics calculations, and more. Mastering this formula not only enriches one's mathematical toolkit but also enhances the understanding of spatial relationships in everyday life.


Grade 10 → 3.2


U
username
0%
completed in Grade 10


Comments