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Калькулятор Нахилу

Calculate the slope, angle, and equation of a line through two points. Find rise over run instantly.

Як користуватися цим калькулятором

  1. Введіть x₁
  2. Введіть y₁
  3. Введіть x₂
  4. Введіть y₂
  5. Натисніть кнопку Розрахувати
  6. Прочитайте результат, відображений під калькулятором

What Is Slope and How to Calculate It

Slope (m) measures the steepness and direction of a line. For two points (x₁,y₁) and (x₂,y₂) on a line: m = (y₂-y₁)/(x₂-x₁) = rise/run. Positive slope means the line goes up from left to right. Negative slope means it goes down. Zero slope = horizontal line. Undefined slope = vertical line (division by zero).

The slope formula is derived from the ratio of vertical change (rise) to horizontal change (run). Example: points (2,3) and (6,11). Rise = 11-3 = 8. Run = 6-2 = 4. Slope m = 8/4 = 2. This means for every 1 unit right, the line goes 2 units up. The angle of inclination θ = arctan(m) ≈ 63.4° for m=2.

The line equation is y = mx + b, where b is the y-intercept (value of y when x=0). Finding b: substitute one point. Using (2,3) with m=2: 3 = 2(2) + b → b = -1. Full equation: y = 2x - 1. This slope-intercept form is the most common way to describe a line in algebra.

Types of Slopes and Parallel/Perpendicular Lines

Slopes can be classified by their sign and magnitude. Positive slope (m > 0): line rises from left to right. Negative slope (m < 0): line falls from left to right. Zero slope (m = 0): horizontal line (y = constant). Undefined slope: vertical line (x = constant), where the denominator x₂-x₁ = 0.

Parallel lines have equal slopes: if line 1 has slope m₁ and line 2 has slope m₂, they're parallel iff m₁ = m₂ (and different y-intercepts). Perpendicular lines have slopes that are negative reciprocals: m₁ × m₂ = -1, or m₂ = -1/m₁. If one line has slope 3, a perpendicular line has slope -1/3.

The slope concept extends to calculus as the derivative: f'(x) is the instantaneous slope of the curve y = f(x) at point x. The slope of a tangent line to a curve at any point equals the derivative at that point. This is the foundational concept of differential calculus, enabling us to optimize functions and analyze rates of change.

Slope in Real-World Applications

Slope appears everywhere in practical applications. In construction and architecture, roof pitch is expressed as rise:run (e.g., 4:12 means 4 inches rise per 12 inches run = slope 1/3). Ramp slope regulations for accessibility: ADA requires maximum slope 1:12 (rise:run) for wheelchair ramps.

In road engineering, grade (slope percentage) determines safety and drainage. Highway grades rarely exceed 6-7% for trucks. A 6% grade means 6 feet of rise per 100 feet of horizontal distance. Steep mountain roads can have 10-15% grades. Ski slopes are described by degree of inclination: beginner (0-25°), intermediate (25-40°), expert (40°+).

In economics and data analysis, slope represents rate of change. In a linear demand curve, slope tells you how much quantity demanded changes per unit price change. In regression analysis, the slope coefficient tells you how much the dependent variable changes per unit change in the independent variable. A slope of 0 in a regression means no linear relationship between variables.

Останнє оновлення: March 2026

Frequently Asked Questions

What does a slope of 0 mean?

A slope of 0 means the line is horizontal — it doesn't rise or fall. The equation is y = b (a constant). In real life: a perfectly flat road has 0% grade.

What is the slope of a vertical line?

A vertical line has undefined slope because the run (x₂-x₁) = 0, causing division by zero. The equation of a vertical line is x = c (a constant). It cannot be written in slope-intercept form.

How do I convert slope to angle?

Angle θ = arctan(slope). For slope m=1: θ = arctan(1) = 45°. For m=2: θ = arctan(2) ≈ 63.4°. Our calculator displays this angle automatically.