Linear Graph – Definition with Examples
11 minutes read
Created: December 24, 2023
Last updated: January 5, 2024
Hello, young explorers of the fascinating world of mathematics! Welcome back to another exciting adventure with Brighterly. Today, we embark on a journey to the land of Linear Graphs. As you’ve come to expect from Brighterly, we’ll explore this topic through simple explanations, fun examples, and engaging exercises to help you comprehend the subject thoroughly.
Remember those playground slides that were straight, either going up, down or staying flat? Imagine if those slides could help us understand how two things relate to each other! That’s exactly what linear graphs are – simple, straight ‘slides’ showing how two elements are connected. By learning about them, you open doors to understanding more complex fields like calculus, statistics, and even computer science.
Whether you’re an ardent math lover, an enthusiastic learner, or a curious mind wanting to unravel the mysteries of mathematics, this journey is for you. So, let’s jump right in!
What is a Linear Graph?
A Linear Graph, in the simplest terms, is a graphical representation of a linear equation in two variables, x and y. It takes the form of a straight line in a two-dimensional coordinate system, reflecting the consistent relationship between the two variables involved. For kids, think of it as a straight slide on a playground: it either goes up, down or is completely flat, but doesn’t bend or curve. This straightforward property makes linear graphs an essential part of mathematics, serving as the basis for more complex fields such as calculus, statistics, and computer science.
Linear graphs are used in a variety of practical applications, from calculating your savings account growth, predicting future populations, understanding the speed of a car to even decoding complex scientific phenomena. Their simplicity, ease of interpretation, and broad applicability make them a crucial part of not only mathematics, but also physics, economics, engineering, and numerous other disciplines.
Linear Graph Definition
A Linear Graph is defined as the graphical representation of a linear equation, typically in the form y = mx + c, where m represents the slope of the line, and c represents the y-intercept. The graph is a straight line that shows the relationship between these two variables. The term ‘linear’ stems from ‘line’ – signifying the straight line nature of the graph.
The slope (m) represents the rate at which y changes for a unit change in x, while the y-intercept (c) represents the value of y when x is zero. For instance, if you’re saving money, the slope could represent the amount you save each month, and the y-intercept could signify how much money you started with.
Linear Graph vs Line Graph
Often, the terms “Linear Graph” and “Line Graph” are used interchangeably, causing confusion. But there’s a vital difference between the two. While both involve the use of lines to depict relationships between variables, their application and meaning differ.
A Linear Graph is specifically the graph of a linear equation, resulting in a straight line that showcases a consistent relationship between two variables. This uniformity results from the fact that for every unit change in the input (x), the output (y) changes by a fixed amount, as determined by the slope.
On the other hand, a Line Graph is a type of graph that is used to display information that changes over time. It need not necessarily represent a linear relationship; the line can be curved or zigzag, reflecting variable changes.
To put it simply, all linear graphs are line graphs, but not all line graphs are linear graphs.
At Brighterly, we believe that practice is the key to mastery. That’s why we invite you to explore our Linear Graph Worksheets, where you can find an array of additional practice questions, complete with answers.
Linear Graph Equation
A Linear Graph Equation is typically represented as y = mx + c, where:
- ‘y’ is the dependent variable (output)
- ‘m’ is the slope of the line
- ‘x’ is the independent variable (input)
- ‘c’ is the y-intercept
For children, think of the linear equation as a recipe. If ‘m’ is the number of cups of flour, ‘x’ the number of cookies you want to bake, and ‘c’ the number of eggs needed, ‘y’ would be the final product (cookies). The equation helps you decide how many cups of flour and eggs you need based on how many cookies you want to make.
Different Parts of a Linear Graph
A Linear Graph has three main components:
- x-axis: It’s the horizontal line where we plot the independent variable (x).
- y-axis: It’s the vertical line where we plot the dependent variable (y).
- Line: The straight line formed by connecting the points that satisfy the linear equation.
In the context of a linear equation y = mx + c:
- Slope (m): It defines the steepness or gradient of the line. It can be positive (line slopes upwards), negative (line slopes downwards), or zero (line is horizontal).
- Y-intercept (c): It’s the point where the line crosses the y-axis, indicating the value of y when x equals zero.
Properties of Linear Graph Equations
Linear Graph Equations have some unique properties:
- The graph is always a straight line. It can slant upwards, downwards, or lie horizontally, but it will not curve or bend.
- The slope is constant throughout. This means that for any unit change in x, the change in y is always the same.
- The y-intercept is the point where the graph intersects the y-axis. It’s the value of y when x equals zero.
How to Plot a Linear Equation on a Graph
Plotting a Linear Equation on a graph is a straightforward process:
- Identify the slope (m) and y-intercept (c) from the equation y = mx + c.
- Mark the y-intercept (c) on the y-axis.
- From the y-intercept, move according to the slope to plot additional points. If the slope is positive, move upwards; if it’s negative, move downwards.
- Connect these points to draw a straight line.
How Is a Linear Graph Different from a Line Graph?
The key distinction between a Linear Graph and a Line Graph is in the relationship they depict. A Linear Graph represents a constant or linear relationship between two variables, portrayed by a straight line. In contrast, a Line Graph shows change over time and the line can take any form – straight, curved, or zigzag, demonstrating variable changes.
Solved Examples on Linear Graph
Example 1: If the equation is y = 2x + 3, the y-intercept is 3, and the slope is 2. Starting from point (0,3) on the y-axis, move two units up for every unit move to the right on the x-axis to plot the graph.
Example 2: For the equation y = -1x + 5, the y-intercept is 5, and the slope is -1. Starting from point (0,5), move one unit down for every unit move to the right to draw the graph.
Practice Problems on Linear Graph
- Plot the graph of the equation y = 3x + 2.
- Plot the graph of the equation y = -2x + 4.
- Plot the graph of the equation y = x – 1.
And that’s it! We have now traversed through the intriguing realm of Linear Graphs. At Brighterly, our aim is always to make learning an enjoyable and enlightening experience. With the help of our journey today, we hope you’ve gained a clear understanding of what linear graphs are, how to identify and plot them, and most importantly, how they differ from line graphs.
The power of linear graphs lies in their simplicity and wide application. They’re not just math tools but a way to understand the world around us. From economics to physics, and even predicting the population of a city, these simple straight lines can show us some amazing things!
Stay curious and keep exploring, because mathematics, just like our world, is filled with endless wonders. Until our next exciting adventure, this is Brighterly, making math brighter for you!
Frequently Asked Questions on Linear Graph
What is a Linear Graph?
A Linear Graph is a graph of a linear equation, and it’s represented by a straight line in a two-dimensional space. It shows a constant relationship between two variables, typically denoted as ‘x’ and ‘y’. For every unit change in ‘x’ (independent variable), there’s a constant change in ‘y’ (dependent variable).
How to identify a Linear Graph?
You can identify a Linear Graph by its distinct features. First, it’s always a straight line, whether it slopes upwards, downwards, or is completely horizontal. Second, the slope, or the change in ‘y’ for a unit change in ‘x’, is constant throughout. Lastly, the graph intercepts the y-axis at a point known as the y-intercept, which is the value of ‘y’ when ‘x’ is zero.
How to plot a Linear Graph?
Plotting a Linear Graph involves a few steps. Start by identifying the slope (m) and the y-intercept (c) from the linear equation y = mx + c. Mark the y-intercept on the y-axis. From this point, move up (if the slope is positive) or down (if the slope is negative) according to the slope value to plot additional points. Connect these points to form a straight line.
What is the difference between a Linear Graph and a Line Graph?
A Linear Graph and a Line Graph are different in their representations. While both use lines, a Linear Graph depicts a constant or linear relationship between two variables, forming a straight line. On the other hand, a Line Graph can represent variable relationships, including linear, and is commonly used to display information that changes over time. The line in a Line Graph can be straight, curved, or even zigzag.
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