Precalculus: Worksheet 2.1 - Algebraic Domains Of Functions7. Find All The Discontinuities (if Any) Of The Following Functions, Then Classify Them As Holes, Vertical Asymptotes (VAs), Or Jumps.a) $f(x)=\frac{x-1}{x^3-x}$b)

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Precalculus: Worksheet 2.1 - Algebraic Domains of Functions

Understanding Discontinuities in Algebraic Functions

In algebraic functions, discontinuities occur when the function is undefined at a particular point or set of points. These discontinuities can be classified into three main categories: Holes, Vertical Asymptotes (VAs), and Jumps. In this worksheet, we will explore the concept of discontinuities and learn how to identify and classify them in algebraic functions.

What are Discontinuities?

A discontinuity in a function occurs when the function is not continuous at a particular point or set of points. In other words, the function is not defined at those points, or the function's graph has a gap or a break at those points. Discontinuities can be caused by various factors, including division by zero, undefined expressions, or infinite limits.

Types of Discontinuities

There are three main types of discontinuities in algebraic functions:

  • Holes: A hole is a discontinuity that occurs when a function is undefined at a particular point, but the function's graph has a hole or a gap at that point. Holes are also known as removable discontinuities.
  • Vertical Asymptotes (VAs): A vertical asymptote is a discontinuity that occurs when a function approaches infinity or negative infinity as x approaches a particular value. VAs are also known as non-removable discontinuities.
  • Jumps: A jump is a discontinuity that occurs when a function has a sudden change in value at a particular point. Jumps are also known as discontinuities with a finite jump.

Finding Discontinuities in Algebraic Functions

To find discontinuities in algebraic functions, we need to identify the points where the function is undefined or has an infinite limit. We can do this by factoring the numerator and denominator of the function, canceling out any common factors, and then identifying the points where the function is undefined.

Example 1: Finding Discontinuities in f(x)=xβˆ’1x3βˆ’xf(x)=\frac{x-1}{x^3-x}

Let's find the discontinuities in the function f(x)=xβˆ’1x3βˆ’xf(x)=\frac{x-1}{x^3-x}. To do this, we need to factor the numerator and denominator of the function.

# Factoring the Numerator and Denominator

## Factoring the Numerator

The numerator of the function is $x-1$. This is already factored.

## Factoring the Denominator

The denominator of the function is $x^3-x$. We can factor this expression as follows:

$x^3-x = x(x^2-1)$

We can further factor the expression $x^2-1$ as follows:

$x^2-1 = (x-1)(x+1)$

So, the denominator can be factored as follows:

$x^3-x = x(x-1)(x+1)$

## Canceling Out Common Factors

Now that we have factored the numerator and denominator, we can cancel out any common factors. In this case, we can cancel out the factor $(x-1)$ from the numerator and denominator.

$f(x) = \frac{x-1}{x(x-1)(x+1)}$

## Identifying Discontinuities

Now that we have canceled out the common factor, we can identify the points where the function is undefined. In this case, the function is undefined when $x=0$, $x=1$, or $x=-1$.

## Classifying Discontinuities

We can classify the discontinuities in this function as follows:

*   **Hole**: The function has a hole at $x=1$.
*   **Vertical Asymptote (VA)**: The function has a vertical asymptote at $x=0$.
*   **Vertical Asymptote (VA)**: The function has a vertical asymptote at $x=-1$.

**Conclusion**

In this worksheet, we learned how to find and classify discontinuities in algebraic functions. We used the function $f(x)=\frac{x-1}{x^3-x}$ as an example and identified the points where the function is undefined. We then classified the discontinuities as holes, vertical asymptotes, or jumps. By following these steps, we can identify and classify discontinuities in any algebraic function.

**Practice Problems**

1.  Find the discontinuities in the function $f(x)=\frac{x^2-4}{x^2-9}$.
2.  Classify the discontinuities in the function $f(x)=\frac{x^2-4}{x^2-9}$.
3.  Find the discontinuities in the function $f(x)=\frac{x^2-4}{x^2-9}$ and classify them as holes, vertical asymptotes, or jumps.

**Answer Key**

1.  The function has a hole at $x=2$ and a vertical asymptote at $x=3$.
2.  The function has a hole at $x=2$ and a vertical asymptote at $x=3$.
3.  The function has a hole at $x=2$ and a vertical asymptote at $x=3$.

**References**

*   [1] "Algebraic Functions" by Math Open Reference. Retrieved from <https://www.mathopenref.com/algebraicfunctions.html>
*   [2] "Discontinuities in Algebraic Functions" by Purplemath. Retrieved from <https://www.purplemath.com/modules/discont.htm><br/>
**Precalculus: Worksheet 2.1 - Algebraic Domains of Functions**

**Q&A: Discontinuities in Algebraic Functions**

**Q: What is a discontinuity in an algebraic function?**

A: A discontinuity in an algebraic function occurs when the function is undefined at a particular point or set of points. This can be caused by division by zero, undefined expressions, or infinite limits.

**Q: What are the three main types of discontinuities in algebraic functions?**

A: The three main types of discontinuities in algebraic functions are:

*   **Holes**: A hole is a discontinuity that occurs when a function is undefined at a particular point, but the function's graph has a hole or a gap at that point.
*   **Vertical Asymptotes (VAs)**: A vertical asymptote is a discontinuity that occurs when a function approaches infinity or negative infinity as x approaches a particular value.
*   **Jumps**: A jump is a discontinuity that occurs when a function has a sudden change in value at a particular point.

**Q: How do I find discontinuities in an algebraic function?**

A: To find discontinuities in an algebraic function, you need to identify the points where the function is undefined or has an infinite limit. You can do this by factoring the numerator and denominator of the function, canceling out any common factors, and then identifying the points where the function is undefined.

**Q: What is the difference between a hole and a vertical asymptote?**

A: A hole is a discontinuity that occurs when a function is undefined at a particular point, but the function's graph has a hole or a gap at that point. A vertical asymptote is a discontinuity that occurs when a function approaches infinity or negative infinity as x approaches a particular value.

**Q: Can a function have both a hole and a vertical asymptote?**

A: Yes, a function can have both a hole and a vertical asymptote. For example, the function $f(x)=\frac{x-1}{x(x-1)(x+1)}$ has a hole at $x=1$ and a vertical asymptote at $x=0$ and $x=-1$.

**Q: How do I classify discontinuities in an algebraic function?**

A: To classify discontinuities in an algebraic function, you need to identify the type of discontinuity that occurs at each point. You can do this by examining the function's graph and identifying the points where the function is undefined or has an infinite limit.

**Q: What is the significance of discontinuities in algebraic functions?**

A: Discontinuities in algebraic functions are significant because they can affect the function's behavior and properties. For example, a function with a hole may have a different limit at that point than a function with a vertical asymptote.

**Q: Can discontinuities be removed from an algebraic function?**

A: Yes, discontinuities can be removed from an algebraic function by canceling out common factors in the numerator and denominator. However, this may not always be possible, and the function may still have a discontinuity at that point.

**Q: How do I determine if a discontinuity is a hole or a vertical asymptote?**

A: To determine if a discontinuity is a hole or a vertical asymptote, you need to examine the function's graph and identify the points where the function is undefined or has an infinite limit. You can also use the following criteria:

*   If the function has a hole at a point, the function's graph will have a hole or a gap at that point.
*   If the function has a vertical asymptote at a point, the function's graph will approach infinity or negative infinity as x approaches that point.

**Q: Can discontinuities be classified as jumps?**

A: Yes, discontinuities can be classified as jumps. A jump is a discontinuity that occurs when a function has a sudden change in value at a particular point.

**Q: How do I find the points where a function has a jump?**

A: To find the points where a function has a jump, you need to examine the function's graph and identify the points where the function has a sudden change in value. You can also use the following criteria:

*   If the function has a jump at a point, the function's graph will have a sudden change in value at that point.
*   If the function has a jump at a point, the function's limit at that point may not exist.

**Q: What is the significance of jumps in algebraic functions?**

A: Jumps in algebraic functions are significant because they can affect the function's behavior and properties. For example, a function with a jump may have a different limit at that point than a function without a jump.

**Q: Can jumps be removed from an algebraic function?**

A: No, jumps cannot be removed from an algebraic function. Jumps are a fundamental property of algebraic functions and cannot be eliminated.

**Q: How do I determine if a function has a jump?**

A: To determine if a function has a jump, you need to examine the function's graph and identify the points where the function has a sudden change in value. You can also use the following criteria:

*   If the function has a jump at a point, the function's graph will have a sudden change in value at that point.
*   If the function has a jump at a point, the function's limit at that point may not exist.

**Q: Can a function have multiple jumps?**

A: Yes, a function can have multiple jumps. For example, the function $f(x)=\frac{x^2-4}{x^2-9}$ has two jumps at $x=2$ and $x=-3$.

**Q: How do I classify multiple jumps in an algebraic function?**

A: To classify multiple jumps in an algebraic function, you need to examine the function's graph and identify the points where the function has a sudden change in value. You can also use the following criteria:

*   If the function has multiple jumps at different points, the function's graph will have multiple sudden changes in value at those points.
*   If the function has multiple jumps at different points, the function's limit at those points may not exist.

**Q: What is the significance of multiple jumps in algebraic functions?**

A: Multiple jumps in algebraic functions are significant because they can affect the function's behavior and properties. For example, a function with multiple jumps may have a different limit at those points than a function without multiple jumps.

**Q: Can multiple jumps be removed from an algebraic function?**

A: No, multiple jumps cannot be removed from an algebraic function. Multiple jumps are a fundamental property of algebraic functions and cannot be eliminated.

**Q: How do I determine if a function has multiple jumps?**

A: To determine if a function has multiple jumps, you need to examine the function's graph and identify the points where the function has a sudden change in value. You can also use the following criteria:

*   If the function has multiple jumps at different points, the function's graph will have multiple sudden changes in value at those points.
*   If the function has multiple jumps at different points, the function's limit at those points may not exist.

**Conclusion**

In this Q&A article, we have discussed the concept of discontinuities in algebraic functions and how to classify them as holes, vertical asymptotes, or jumps. We have also discussed the significance of discontinuities and how they can affect the function's behavior and properties. By following these steps, you can identify and classify discontinuities in any algebraic function.

**Practice Problems**

1.  Find the discontinuities in the function $f(x)=\frac{x^2-4}{x^2-9}$.
2.  Classify the discontinuities in the function $f(x)=\frac{x^2-4}{x^2-9}$.
3.  Find the points where the function $f(x)=\frac{x^2-4}{x^2-9}$ has a jump.

**Answer Key**

1.  The function has a hole at $x=2$ and a vertical asymptote at $x=3$.
2.  The function has a hole at $x=2$ and a vertical asymptote at $x=3$.
3.  The function has a jump at $x=2$ and $x=-3$.

**References**

*   [1] "Algebraic Functions" by Math Open Reference. Retrieved from <https://www.mathopenref.com/algebraicfunctions.html>
*   [2] "Discontinuities in Algebraic Functions" by Purplemath. Retrieved from <https://www.purplemath.com/modules/discont.htm>