Slope and Y-Intercept Calculator
Enter the coordinates of two distinct points to calculate the slope (m) and y-intercept (b) of the line passing through them. The calculator will also provide the equation of the line in the form y = mx + b.
Understanding Slope and Y-Intercept
In mathematics, particularly in algebra and geometry, the slope and y-intercept are fundamental characteristics of a straight line. They provide crucial information about the line's orientation and position on a coordinate plane.
What is Slope (m)?
The slope, often denoted by 'm', measures the steepness and direction of a line. It represents the "rise over run" – how much the y-coordinate changes for a given change in the x-coordinate. A positive slope indicates an upward trend from left to right, a negative slope indicates a downward trend, a zero slope means the line is horizontal, and an undefined slope means the line is vertical.
The formula for calculating the slope (m) between two points (x₁, y₁) and (x₂, y₂) is:
m = (y₂ – y₁) / (x₂ – x₁)
What is Y-Intercept (b)?
The y-intercept, often denoted by 'b', is the point where the line crosses the y-axis. At this point, the x-coordinate is always zero (0, b). It represents the initial value or starting point of a linear relationship when the independent variable (x) is zero.
Once the slope (m) is known, the y-intercept (b) can be calculated using one of the points (x₁, y₁) and the slope:
b = y₁ – m * x₁
The general equation of a straight line is given by:
y = mx + b
How to Use This Calculator
- Enter the x and y coordinates for your first point (x₁, y₁) into the respective fields.
- Enter the x and y coordinates for your second point (x₂, y₂) into the respective fields.
- Click the "Calculate Slope & Y-Intercept" button.
- The calculator will display the calculated slope, y-intercept, and the equation of the line.
Example Calculation
Let's say we have two points: Point 1 (2, 5) and Point 2 (6, 13).
Step 1: Calculate the Slope (m)
x₁ = 2, y₁ = 5
x₂ = 6, y₂ = 13
m = (13 – 5) / (6 – 2)
m = 8 / 4
m = 2
Step 2: Calculate the Y-Intercept (b)
Using Point 1 (2, 5) and m = 2:
b = y₁ – m * x₁
b = 5 – 2 * 2
b = 5 – 4
b = 1
Step 3: Formulate the Equation of the Line
With m = 2 and b = 1, the equation of the line is:
y = 2x + 1
This calculator automates these steps for any two given points.