Slope of the Line

Slope of the Line could be found by using two points on the line by finding the rise and the run. The rise is the vertical change between two places, whereas the run is the horizontal change. The slope equals the rise divided by the run which means that Slope= rise run.

Slope of the Line

:black_small_square: The Slope

In mathematics, a line’s slope or gradient is a number that specifies the line’s direction as well as its steepness. The letter m is frequently used to represent slope; there is no clear answer to why the letter m is used for slope.

But it can be found in O’Brien (1844), who wrote the equation of a straight line as “y = MX + b,” and in Tod Hunter (1888), who wrote it as “y = MX + c.”

The ratio of “vertical change” to “horizontal change” between (any) two unique points on a line is used to compute the slope. The ratio is sometimes written as a quotient (“rise over run”), which gives the same value for every two different points on a single line.

The “rise” of a falling line is negative. A road surveyor may draw the line, or it may appear in a diagram that depicts a road or a roof as a description or a design.

The absolute value of the slope is used to determine the steepness, inclination, or grade of a line. A steeper line is indicated by a slope with a higher absolute value. A line might be growing, decreasing, horizontal, or vertical in direction.

If a line rises from left to right, it is growing. The slope is positive, i.e. display style m>. If a line descends from left to right, it is decreasing. The slope is negative.

The slope of a horizontal line is zero. This is a function that never changes. The slope of a vertical line is indeterminate.

The difference in the altitudes of the road at those two sites, say y1 and y2, is the rise of the road between those two points, or in other words, the rise equals (y2 y1) = y.

The run is the change in distance from a given point measured along with a level, horizontal line, or in other words, the run is (x2 x1) = x over relatively small distances when the earth’s curvature can be ignored.

The ratio of the altitude change to the horizontal distance between any two spots on the line is used to represent the slope of the road between the two points.

The line’s slope m is expressed mathematically as:


In geography and civil engineering, the idea of slope refers to slopes or gradients. The tangent function relates the slope m of a line to its angle of inclination using trigonometry.

M= tan (theta)

Thus, the slope of a 45° rising line is +1, while the slope of a 45° falling line is 1. The mathematics of differential calculus defines the slope of a curve at a point as the slope of the tangent line at that point as a generalization of this practical definition.

When the curve is represented by a sequence of points in a diagram or a list of point coordinates, the slope can be determined between any two specified points rather than at a single point.

When a curve is provided as a continuous function, such as an algebraic formula, differential calculus gives principles that yield a formula for the curve’s slope at any point in the center.

This broadening of the idea of slope enables the design and building of extremely complex structures that go beyond static horizontal and vertical structures and may vary over time, move in curves, and alter based on the rate of change of other variables.

As a result, the simple concept of slope becomes one of the most important foundations of contemporary technology and the built environment.


A slope is the degree of steepness of a hill. The same may be said about a line’s steepness. The slope is the ratio of vertical change between two points (rise) to horizontal change between the same two points (run). The letter m is commonly used to denote the slope of a line.

:black_small_square: Slope of a Line

The change in y-values divided by the change in x-values is the slope of a line. This value represents the steepness of a line.

The slope of a line in the plane including the x and y axes is defined as the change in the y coordinate divided by the corresponding change in the x coordinate between two independent locations on the line and is commonly symbolized by the letter m.

The following equation describes this:

m= vertical change/horizontal change = rise/run

A line’s slope does not define it, but it does provide us with a lot of information. It’s also a crucial component of a line’s equation.

Because the slope of a line is frequently a fraction, it’s a good idea to brush up on fractions before moving on to this subject. It’s also a good idea to brush up on coordinate geometry and the coordinate plane.

A line’s slope is a number that indicates how steep a line is. This can be a positive, negative, or zero number. It might be rational or irrational as well. A line’s slope isn’t the only thing that defines it.

This implies that even if you know the slope of a line, you won’t be able to identify exactly which points it passes through. Any line with the same slope is referred to be a parallel line.

When a line is rotated 90 degrees, it becomes perpendicular to the other. When two perpendicular lines intersect, four 90-degree angles are formed. A line’s slope isn’t the only thing that defines it.

This implies that even if you know the slope of a line, you won’t be able to identify exactly which points it passes through.

Any line with the same slope is referred to be a parallel line. When a line is rotated 90 degrees, it becomes perpendicular to the other. When two perpendicular lines intersect, four 90-degree angles are formed.

:small_orange_diamond: Calculating the slope of the line

The letter m is commonly used to signify slope. Surprisingly, no one seems to know why this letter was picked. Anyone who understands French, on the other hand, will have no trouble remembering this because “monster” implies “to climb.”

Because mountains have slopes, this term has the same origin as the English word mountain, which may likewise be used as a mnemonic.

By dividing the change in y-values by the change in x-values, we can get the slope. Because the ratio remains constant, it doesn’t matter whatever coordinates we use for this computation.

Finding two coordinate pairs for points on a line is the simplest technique to get a slope. These two positions are referred to be (x1, y1) and (x2, y2). It is important to note that it makes no difference which point is labeled which.

m= (y1-y2) is the slope formula (x1-x2).

So that you don’t unintentionally swap the x and y variables in the calculation, remember that slope is “rise overrun.”

Label the first point (x1, y1) and the second point (-1, -1), if a line goes through the points (1, 2) and (-1, 1). (X2, y2).

We should start by locating two locations on the line. It’s logical to select the simplest points possible, thus the origin and points (1, 2) are the best choices.

We must travel “up to two (units), over one (unit right)” to get from the first to the second point. The slope is shown by saying this aloud while counting the units. In this example, the answer is 21 (or “two over one”).

By entering the values into the formula above, we can double-check. If (0, 0) equals (x1, y1) and (1, 2) equals (x2, y2), we get the following:

m= (0-2) ⁄ (0-1) =-2⁄-1=2.

It’s worth noting that using a graph to assess slope only works if the data set contains rational integers that are simple to detect on the graph’s scale.


The slope-intercept form of an equation occurs when the equation of a line is stated in the form y = MX + b. The slope of the line is denoted by the letter m. And b is the value of b in the y-intercept point (0, b). The slope of the equation y = 3x – 7 is 3, and the y-intercept is (0, 7) for example.

:black_small_square: Type of slopes

Type of slope Visual description Verbal description
Positive Uphill Increasing
Negative Downhill Decreasing
0 Horizontal Constant
Undefined Vertical N/A

There are four different types of slopes:

  • Positive

  • Negative

  • Zero slope

  • Undefined slope

:small_orange_diamond: 1. Positive slope

The two values are shown along the x-axis and the y-axis is directly connected when the slope is positive. When one quantity increases or decreases, another quantity increases or decreases at the same time.

A positively sloped line has m > 0, and the angle formed by this line with the positive x-axis is sharp, so that 0o 90o. A line with a positive slope has a positive rise to run ratio.

The rise represents the change in y value, which is denoted by y, and the run represents the change in x value, which is denoted by x.

Positive Slope (m) = +rise/run = +Δy/Δx

A positive slope indicates a direct relationship between the two variables. When the x value rises, the value rises with it. Alternatively, we can see that when the x value falls, the value falls as well.

An acute angle is formed by a line with a positive slope that is anti-clockwise with regard to the positive x-axis or a line parallel to the x-axis. This acute angle is less than a straight angle (90o-), and the line’s slope is upward.

m = +Tanθ

From left to right, the line with a positive slope is going upwards.

:small_orange_diamond: 2. Negative slope= Negative Correlation

The following variables have a negative association when the slope is negative:

  • x and y variables

  • Both the input and the output

  • Variables that are independent and dependent

  • The relationship between cause and effect

When the two variables of a function move in opposing directions, a negative correlation develops. As the value of x rises, so does the value of y. Similarly, when the value of x falls, the value of y rises.

A negative correlation, on the other hand, denotes a definite association between the variables, implying that one influences the other significantly.

In a scientific experiment, a negative correlation means that increasing the independent variable (the one the researcher manipulates) causes the dependent variable to drop (the one measured by the researcher).

A scientist could discover, for example, that when predators are added to the habitat, the number of prey decreases. In other words, the number of predators and the amount of prey has a negative relationship.

:small_orange_diamond: 3. Zero slopes

We usually conceive of slope in terms of ‘rise over run,’ or how much y changes as x changes. Consider the following scenario: you’re riding your bicycle down a straight road.

You begin near the beach and stop for lunch at a location 10 miles distant. You’re. 25 miles above sea level at this lunch stop. You compute slope, or increase overrun, to assess how steep your ascent was:

Slope = .25/10 = 1/40

Make sure the increase, which is a vertical climb, is at the very top of the proportion.

It’s absolutely OK to write 1/40 as the decimal equivalent, 0.025, but it’s not required. Because they make intuitive sense, slopes are frequently represented as functions.

A slope of 1/40, for example, indicates that for every 40 units moved horizontally, you rise 1 unit vertically. ‘Units’ might be in the form of feet, meters, or kilometers. It makes no difference whether you rode your bike on a perfectly straight, continually climbing course.

Now, a slope of 1/40 may appear insignificant, but it would be felt by your legs if you rode a bicycle for 10 kilometers. If you want a very comfortable ride, go for a slope that is even less than 1/40.

The simplest ride, without really cycling downhill, would be on a completely level road. So, no matter how long your bike, you want to rise 0 miles (or 0 feet, or 0 meters).

In other words, you want 0 in the numerator when calculating slope, rise overrun (the top of the fraction). It doesn’t really matter what’s on the bottom. Your ride will be flat no matter how far you go.

:small_orange_diamond: 4. Undefined Slope

The tangent of a straight line’s inclination to the x-axis is indicated by,’ i.e. if the inclination of a line is, its slope is m = tan. The vertical line is a straight line that is either parallel to the y-axis or coincides with it.

When the angle of inclination of vertical lines is 90°, the slope m = tan 90° = undefined. Another method is to use slope = rise/run. There is no run at all for vertical lines, hence the denominator is zero. We end up with an amorphous slope.

Since tan 90° is undefined, the slope of the y-axis, as well as the slope of any straight line parallel to the y-axis, is undefined. A straight line with an unknown slope has the equation x = a, where a can be any real value and is a constant.

It indicates that, regardless of the points chosen, every point on the line has the x coordinates as ‘a’. The x-intercept, or point where the line crosses the x-axis, is denoted by the letter ‘a.’

Here are several undefined slope formulae.

  • x = 0 is the equation for the y-axis.

  • The line traveling through the points (-5, 2) and (-5, -3) has the equation x = -5.

  • The line going through (3, -4) with an unknown slope has the equation x = 3.

Elevators that only move up and down, a mountain cliff that is vertical up to a finite distance that a mountaineer finds difficult to climb, skyscrapers, lamp posts, or flag posts, the sides of doors or windows, the legs of the chair, the rocket at the time of launch, and so on are all examples of the undefined slope.

A vertical line is a perpendicular line to the x-axis with an unknown slope, as we know. If a line passes through two coordinates, (x1, y1) and (x1, y2), it is obvious that the x-coordinates are the same.

They’re the points on a vertical line that’s the same length. As a result, the slope of such a line will be ambiguous. The slope of horizontal lines parallel to the x-axis is zero, whereas the slope of vertical lines parallel to the y-axis is undefined.

A line with zero slopes has a graph of y = b, whereas one with an indeterminate slope has a graph of x = a, where ‘b’ and 'a are they and x-intercepts, respectively.

  • Any line that is parallel to the y-axis, i.e. a vertical line, has an undefined slope.

  • x =a is an undefined slope graph, where ‘a’ is the constant value of the x-coordinate throughout the line.

  • The slope-intercept form cannot be used to depict a line with an undefined slope since there is no y-intercept.

To be precise

The slope is a mathematical term that expresses how steep a straight line is. It’s also known as the gradient. The slope of a line is defined as the “change in y” divided by the “change in x.” If you choose two points on a line (x1,y1) and (x2,y2), you may find the slope by dividing y2 - y1 by x2 - x1.

Frequently Asked Questions:

Here are some questions about Slope of the Line:

1. How well-versed are you on the subject of the slope?

The inclination of a line relative to the horizontal is measured numerically as slope. The slope of any line, ray, or line segment in analytic geometry is equal to the ratio of vertical to the horizontal distance between any two points on it (“slope equals rise over run”).

2. What are the guidelines for calculating slope?

Rules are as follows:

  • On the line, find two points.

  • Count the increase. To go from one point to the next, how many units do you count up or down. As the numerator, write down this number.

  • Count the units. To get to the point, how many units do you count to the left or right

  • If at all feasible, simplify your fraction.

3. What can we learn from slopes?

The steepness of a line is described by its slope. Any line’s slope remains constant along its length. The slope can also provide information about the line’s orientation in the coordinate plane. The slope may be computed using the coordinates of any two points on a line or by looking at the graph of a line.

4. Is a number always a number when it comes to slope?

Correct. Using the slope formula, you discovered that. You’ve only studied lines that go “uphill” or “downhill” so far. They might have steep or gentle slopes, but they are always positive or negative values.

5. Is it possible for the slope to be a mixed number?

Rise over run is a type of slope that may be defined as a rate of change or a ratio. In equations, the letter is frequently used to represent it. It can be a decimal number, although it’s more likely to be expressed as a fraction or a mixed number.

6. What is the definition of a slope’s rise?

The ratio of vertical and horizontal variations between two points on a surface or a line is known as the slope in mathematics. The rise is the vertical change between two places, whereas the run is the horizontal change. The slope is calculated by dividing the increase by the run.

7. What is the slope value?

The absolute value of the slope is used to determine the steepness, inclination, or grade of a line. A steeper line is indicated by a slope with a higher absolute value. A line might be growing, decreasing, horizontal, or vertical in direction. The slope of a horizontal line is zero.

8. What if there isn’t any slope?

A vertical line will always have no slope, and “the slope is undefined” or “the line has no slope” indicates that the line is vertical. By the way, all vertical lines have the form “x = some number,” with “x = some number” indicating that the line is vertical.

9. Is it possible for a slope to be a fraction?

Slopes can be positive or negative and can be whole integers or fractions. All slopes may be expressed as a fraction, which shows you how much the line varies in the y-direction relative to how much it changes in the x-direction. As the expression “rise over run” suggests, this is simple to remember.

10. How can you make the slope smaller?

If you’re not sure, write down the factors of both integers and choose the one with the highest common factor. Subtract this value from the numerator. The simplified slope of the line is also 0 if the outcome is zero. Subtract the highest common factor from the denominator.


To conclude the topic about Slope of the Line, we can say that some real-life instances of slope include determining how steep a road will be when it is being built. In order to determine the hazards, speeds, and other factors, skiers and snowboarders must analyze the slopes of hills. The slope is a crucial concern when building wheelchair ramps.

Related Articles

Parallel line equation
Least squares regression line equation