The Distance Formula: Understanding (x2 - x1)² + (y2 - y1)²
The expression (x2 - x1)² + (y2 - y1)² is a fundamental formula in mathematics, representing the distance between two points in a two-dimensional plane. This formula is known as the distance formula and is derived from the Pythagorean theorem.
Understanding the Formula
Let's break down the formula:
- (x1, y1) and (x2, y2) represent the coordinates of two points in the Cartesian plane.
- (x2 - x1) represents the difference in the x-coordinates of the two points. This essentially calculates the horizontal distance between the points.
- (y2 - y1) represents the difference in the y-coordinates of the two points. This calculates the vertical distance between the points.
- Squaring the horizontal and vertical distances gives us the squared lengths of the sides of a right triangle formed by connecting the two points and drawing a horizontal and vertical line.
- Adding the squared distances represents applying the Pythagorean theorem, where the sum of the squares of the legs of a right triangle equals the square of the hypotenuse. The hypotenuse in this case is the line connecting the two points, which is the distance we want to find.
- Taking the square root of the entire expression finally gives us the distance between the two points.
Application in Real-World Scenarios
The distance formula is crucial in various real-world applications:
- Navigation: GPS systems utilize the distance formula to calculate the distance between two locations on a map.
- Engineering: Architects and engineers use the distance formula to calculate the length of structures, such as bridges and buildings.
- Computer Science: The formula is used in various algorithms, including pathfinding and collision detection in games and simulations.
- Physics: The distance formula is used in various physics calculations, such as calculating the distance traveled by an object or the magnitude of a force.
Examples
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Find the distance between the points (2, 3) and (5, 7).
- x1 = 2, y1 = 3, x2 = 5, y2 = 7
- Distance = √((5-2)² + (7-3)²)
- Distance = √(3² + 4²)
- Distance = √(9 + 16)
- Distance = √25 = 5
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Find the distance between the points (-1, 4) and (3, -2).
- x1 = -1, y1 = 4, x2 = 3, y2 = -2
- Distance = √((3 - (-1))² + (-2 - 4)²)
- Distance = √(4² + (-6)²)
- Distance = √(16 + 36)
- Distance = √52 = 2√13
Conclusion
The distance formula, represented by (x2 - x1)² + (y2 - y1)², is a fundamental concept in mathematics with wide-ranging applications in various fields. It allows us to calculate the distance between two points in a plane, which is essential for solving numerous real-world problems.