How to Find Discontinuities of Rational Functions?
Discontinuities of rational functions occur when the denominator is \(0\). Read this post to know more about finding discontinuities of rational functions.
[include_netrun_products_block from-products="product/6-south-carolina-sc-ready-grade-3-math-practice-tests/" product-list-class="bundle-products float-left" product-item-class="float-left" product-item-image-container-class="p-0 float-left" product-item-image-container-size="col-2" product-item-image-container-custom-style="" product-item-container-size="" product-item-add-to-cart-class="btn-accent btn-purchase-ajax" product-item-button-custom-url="{url}/?ajax-add-to-cart={id}" product-item-button-custom-url-if-not-salable="{productUrl} product-item-container-class="" product-item-element-order="image,title,purchase,price" product-item-title-size="" product-item-title-wrapper-size="col-10" product-item-title-tag="h3" product-item-title-class="mt-0" product-item-title-wrapper-class="float-left pr-0" product-item-price-size="" product-item-purchase-size="" product-item-purchase-wrapper-size="" product-item-price-wrapper-class="pr-0 float-left" product-item-price-wrapper-size="col-10" product-item-read-more-text="" product-item-add-to-cart-text="" product-item-add-to-cart-custom-attribute="title='Purchase this book with single click'" product-item-thumbnail-size="290-380" show-details="false" show-excerpt="false" paginate="false" lazy-load="true"]
Whenever we want to discover the point of discontinuity of any function, we just have to set the denominator to zero.
Related Topics
A step-by-step guide to the discontinuities of rational functions
In rational functions, points of discontinuity refer to fractions that are undefined or have zero denominators. When the denominator of a fraction is \(0\), it becomes undefined and appears as a whole or a break in the graph.
To find discontinuities of rational functions, follow these steps:
- Obtain a function’s equation. Note that if the numerator and denominator expressions have any similar factors, they should be wiped out.
- Rewrite the denominator expression as a zero-valued equation.
- Solve the equation for the denominator.
The Discontinuities of Rational Functions – Example 1:
Find the discontinuities of \(f(x)=\frac{x-1}{x^2-x-6}\).
First, setting the denominator equal to zero: \(x^2-x-6=0\).
Then factoring it out: \(x^2-x-6=0\) ⇒ \((x+2)(x-3)=0\)
\(x+2=0 ⇒ x=-2\)
\(x-3=0 ⇒x=3\)
Now, \(f\) is discontinuous at \(x=-2\) and \(x=3\).
The Discontinuities of Rational Functions – Example 2:
Find the discontinuities of \(f(x)=\frac{1}{x^2-4}\).
First, setting the denominator equal to zero: \(x^2-4=0\).
Then factoring it out: \(x^2-4=0\) ⇒ \((x+2)(x-2)\).
\(x+2=0\) ⇒ \(x=-2\)
\(x-2=0\) ⇒ \(x=2\)
Now, \(f\) is discontinuous at \(x=-2\) and \(x=2\).
Exercises for the Discontinuities of Rational Functions
Find the discontinuities of rational functions.
- \(\color{blue}{f(x)=\frac{x+2}{x^2-5x-6}}\)
- \(\color{blue}{f(x)=\frac{x-2}{x^2-2x-35}}\)
- \(\color{blue}{f(x)=\frac{x^2-6x+8}{x-5}}\)
- \(\color{blue}{f(x)=\frac{x+10}{x^2-10x+21}}\)
- \(\color{blue}{x=-1, x=6}\)
- \(\color{blue}{x=7, x=-5}\)
- \(\color{blue}{x=5}\)
- \(\color{blue}{x=3, x=7}\)
Related to This Article
More math articles
- The Enchanted Forest of How to Compare Ratios – A Tale of Mathematical Adventure
- What Is a Good ALEKS Score?
- 10 Most Common 7th Grade Common Core Math Questions
- Everything You Need to Know to Choose the Right Laptop
- GED Math Practice Test & Sample [Updated for 2026]
- How to Evaluate Decimal Distances on the Map
- How to Master the Squeeze Theorem for Calculating Limits
- The Ultimate TSI Math Course (+FREE Worksheets & Tests)
- The Intermediate Value Theorem
- Top 10 4th Grade MCAS Math Practice Questions



























What people say about "How to Find Discontinuities of Rational Functions? - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.