Graphical limit at point discontinuity

Alphabets Sounds Video

share us on:

This lesson explores the concept of limits in relation to points of discontinuity in functions, specifically examining the function \( g(x) \) as \( x \) approaches 7. It demonstrates that while the limit of \( g(x) \) from both the left and right sides as \( x \) nears 7 is 0, the actual value of the function at that point is 3, indicating a removable discontinuity. Understanding this relationship is crucial for analyzing function behavior in calculus.

Understanding Limits and Discontinuities in Functions

In this article, we will delve into the concept of limits, particularly focusing on how they relate to points of discontinuity in functions. We will examine the behavior of the function ( g(x) ) as the input nears a specific value, specifically ( x = 7 ).

Identifying the Point of Discontinuity

The function ( g(x) ) has a point of discontinuity at ( x = 7 ). To understand the limit of ( g(x) ) as ( x ) approaches 7, we need to evaluate the function from both the left and right sides of this point.

Evaluating the Limit from the Left

As we approach ( x = 7 ) from values less than 7, we observe the following:

  • For ( g(3) ), ( g(4) ), ( g(5) ), and ( g(6) ), the values are plotted on a graph.
  • Specifically, ( g(6) ) is slightly less than -1, and ( g(6.5) ) is around -0.5.
  • As we get closer to 7, for ( g(6.9) ) and ( g(6.99) ), the values approach 0 but remain slightly less than zero.

From this analysis, it appears that as ( x ) approaches 7 from the left, ( g(x) ) approaches 0.

Evaluating the Limit from the Right

Now, let’s consider the values of ( g(x) ) as ( x ) approaches 7 from the right:

  • For ( g(8) ) and ( g(9) ), the values are significantly higher, around 2 and 6, respectively.
  • As we examine values closer to 7, such as ( g(7.5) ), ( g(7.1) ), and ( g(7.01) ), these values are slightly greater than 0.
  • Continuing this trend, ( g(7.0000001) ) also approaches 0.

Thus, as ( x ) approaches 7 from the right, ( g(x) ) also approaches 0.

Conclusion: The Limit and Discontinuity

From both sides, we find that the limit of ( g(x) ) as ( x ) approaches 7 is 0. However, it’s important to note that the actual value of the function at ( x = 7 ) is ( g(7) = 3 ). This discrepancy indicates a point of discontinuity, often referred to as a removable discontinuity.

In summary, when the limit of a function as it approaches a certain value does not equal the function’s actual value at that point, it signifies a discontinuity. Understanding these concepts is essential for analyzing the behavior of functions in calculus.

  1. Reflect on your understanding of limits before reading the article. How has your perspective on limits and their relation to discontinuities changed after reading?
  2. Consider the function ( g(x) ) discussed in the article. How does evaluating the limit from both the left and right sides enhance your understanding of the function’s behavior at ( x = 7 )?
  3. What insights did you gain about the concept of removable discontinuity, and how might this knowledge be applied in other areas of mathematics or real-world scenarios?
  4. How does the discrepancy between the limit of ( g(x) ) as ( x ) approaches 7 and the actual value ( g(7) = 3 ) illustrate the importance of understanding limits in calculus?
  5. In what ways do you think the graphical representation of ( g(x) ) values helps in comprehending the concept of limits and discontinuities?
  6. Discuss any challenges you encountered while trying to understand the behavior of ( g(x) ) as ( x ) approaches 7. How did the article help clarify these challenges?
  7. How might the concepts of limits and discontinuities be relevant to fields outside of mathematics, such as physics or engineering?
  8. After reading the article, what further questions do you have about limits and discontinuities that you would like to explore?
  1. Graphical Analysis of Limits

    Create a graph of the function ( g(x) ) using a graphing tool or software. Plot the points mentioned in the article, especially focusing on the behavior as ( x ) approaches 7 from both the left and the right. Analyze the graph to visually confirm the limit and identify the point of discontinuity. Discuss your findings with your peers.

  2. Limit Calculation Exercise

    Calculate the limit of ( g(x) ) as ( x ) approaches 7 from both sides using the epsilon-delta definition of a limit. Write a short report explaining each step of your calculation and how it relates to the concept of discontinuity.

  3. Peer Teaching Session

    Pair up with a classmate and take turns explaining the concept of limits and discontinuities to each other. Use examples from the article and create new examples to reinforce your understanding. Provide feedback to each other on clarity and comprehension.

  4. Interactive Limit Exploration

    Use an online interactive tool or applet that allows you to manipulate the function ( g(x) ) and observe how the limit changes as ( x ) approaches different values. Experiment with different types of discontinuities and document your observations in a learning journal.

  5. Case Study Analysis

    Research a real-world application where understanding limits and discontinuities is crucial, such as in engineering or economics. Present a case study to the class, explaining how these mathematical concepts are applied and why they are important in that context.

LimitsThe value that a function or sequence “approaches” as the input or index approaches some value. – As x approaches 0, the limit of sin(x)/x is 1.

DiscontinuityA point at which a mathematical function is not continuous. – The function has a discontinuity at x = 2, where the graph has a jump.

FunctionsRelations between a set of inputs and a set of permissible outputs with the property that each input is related to exactly one output. – In calculus, we often study the derivative of functions to understand their rates of change.

EvaluateTo calculate the value of a function for a specific input. – To evaluate the integral, we need to find the antiderivative of the function.

ApproachTo get closer to a particular value or condition, often used in the context of limits. – As x approaches infinity, the function f(x) approaches a horizontal asymptote.

BehaviorThe manner in which a function acts or operates, especially as it relates to its limits and continuity. – The behavior of the function near the asymptote is crucial for understanding its graph.

GraphA visual representation of a function or relation, typically in a coordinate plane. – The graph of the derivative can provide insights into the increasing or decreasing nature of the original function.

ValueThe numerical quantity determined by a function for a given input. – The value of the function at x = 3 is 7, indicating the point (3, 7) on the graph.

RemovableA type of discontinuity that can be “fixed” by redefining the function at a point. – The discontinuity at x = 1 is removable because the limit exists as x approaches 1.

CalculusA branch of mathematics that studies continuous change, encompassing derivatives and integrals. – Calculus is essential for understanding the dynamics of systems in physics and engineering.

All Video Lessons

Login your account

Please login your account to get started.

Don't have an account?

Register your account

Please sign up your account to get started.

Already have an account?