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Dec 8, 2025

3 pages

Understanding the Factor Theorem

Polynomial functions may seem tricky, but they're actually super useful... Show more

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480/81
Days 9
Notes
OBJECTIVES:
1) Identify the possible rational zeros of a polynomial function.
2) Find all the roots of a polynomial func

Understanding Polynomial Roots and Theorems

Ever wondered where a graph crosses the x-axis? Those points are called roots or zeros of a polynomial function. For example, the function f(x) = x³ - 2x² - 5x + 6 has zeros at -2, 1, and 3.

Before diving into new concepts, let's review factoring. When we factor a polynomial like 2x² + 8x + 6, we get 2x+1x+1x+3x+3. The factors directly connect to the zeros—if x2x-2 is a factor, then 2 is a zero!

The Remainder Theorem gives us a cool shortcut: When you divide a polynomial f(x) by xrx-r, the remainder equals f(r). For instance, if you divide 4x² - 3x + 6 by x2x-2, the remainder is 16, which is exactly what you get when you calculate f(2).

💡 Quick Tip: To check if a number might be a zero of a polynomial, just plug it in! If f(r) = 0, then xrx-r is definitely a factor of your polynomial.

This relationship between factors and zeros makes solving polynomial equations much easier once you understand the pattern.

480/81
Days 9
Notes
OBJECTIVES:
1) Identify the possible rational zeros of a polynomial function.
2) Find all the roots of a polynomial func

The Factor Theorem and Finding Zeros

The Factor Theorem is your best friend for polynomial factoring! It states that xbx-b is a factor of f(x) if and only if f(b) = 0. This powerful theorem lets you quickly test potential factors.

Let's see it in action: To check if x+3x+3 is a factor of f(x) = 2x³ + 11x² + 18x + 9, we calculate f(-3). Since f(-3) = 0, we confirm that x+3x+3 is indeed a factor!

But how do we find all possible rational zeros? For a polynomial like f(x) = x³ - 2x² - 5x + 6, we look at factors in the form ±p/q, where p = factors of the constant term (6), and q = factors of the leading coefficient (1). This gives us ±1, ±2, ±3, ±6 as possible rational zeros.

🔍 Remember: Not all possible rational zeros will actually be zeros, but the actual zeros must be in this list!

Once we've found one zero likef(1)=0like f(1) = 0, we can use synthetic division to divide the polynomial by x1x-1. This gives us a quadratic factor x2x6x² - x - 6 that we can further factor into x3x-3x+2x+2. Our complete factorization is x1x-1x3x-3x+2x+2.

480/81
Days 9
Notes
OBJECTIVES:
1) Identify the possible rational zeros of a polynomial function.
2) Find all the roots of a polynomial func

Factoring Complex Polynomials

Ready to tackle more challenging polynomials? Let's work through some examples to build your confidence.

For f(x) = 4x³ - 5x² - 23x + 6, we know f(-2) = 0, so x+2x+2 is a factor. Using synthetic division with -2, we get a quadratic expression 4x² - 13x + 3, which factors as 4x14x-1x3x-3. The complete factorization is x+2x+2x3x-34x14x-1.

When working with higher degree polynomials like f(x) = 4x⁴ - 5x³ - 26x² + 9x + 18, start by finding one zero likef(1)=0like f(1) = 0, then use synthetic division repeatedly. This methodical approach breaks down the problem into manageable steps.

🌟 Pro Strategy: After finding one factor, always divide the polynomial by that factor to simplify your work. Keep repeating this process until you reach a quadratic expression that you can factor.

You can handle even challenging polynomials like x³ - 3x² - 16x - 12 by systematically testing possible zeros and using synthetic division. With practice, you'll start to recognize patterns and develop an intuition for finding factors quickly!



We thought you’d never ask...

What is the Knowunity AI companion?

Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.

Where can I download the Knowunity app?

You can download the app in the Google Play Store and in the Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

Paul T

iOS user

 

Algebra 2

26

Dec 8, 2025

3 pages

Understanding the Factor Theorem

Polynomial functions may seem tricky, but they're actually super useful in math! In these notes, we'll explore how to find all the roots (zeros) of polynomial functions using some clever techniques like the Factor Theorem and identifying possible rational zeros.

480/81
Days 9
Notes
OBJECTIVES:
1) Identify the possible rational zeros of a polynomial function.
2) Find all the roots of a polynomial func

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Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Understanding Polynomial Roots and Theorems

Ever wondered where a graph crosses the x-axis? Those points are called roots or zeros of a polynomial function. For example, the function f(x) = x³ - 2x² - 5x + 6 has zeros at -2, 1, and 3.

Before diving into new concepts, let's review factoring. When we factor a polynomial like 2x² + 8x + 6, we get 2x+1x+1x+3x+3. The factors directly connect to the zeros—if x2x-2 is a factor, then 2 is a zero!

The Remainder Theorem gives us a cool shortcut: When you divide a polynomial f(x) by xrx-r, the remainder equals f(r). For instance, if you divide 4x² - 3x + 6 by x2x-2, the remainder is 16, which is exactly what you get when you calculate f(2).

💡 Quick Tip: To check if a number might be a zero of a polynomial, just plug it in! If f(r) = 0, then xrx-r is definitely a factor of your polynomial.

This relationship between factors and zeros makes solving polynomial equations much easier once you understand the pattern.

480/81
Days 9
Notes
OBJECTIVES:
1) Identify the possible rational zeros of a polynomial function.
2) Find all the roots of a polynomial func

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

The Factor Theorem and Finding Zeros

The Factor Theorem is your best friend for polynomial factoring! It states that xbx-b is a factor of f(x) if and only if f(b) = 0. This powerful theorem lets you quickly test potential factors.

Let's see it in action: To check if x+3x+3 is a factor of f(x) = 2x³ + 11x² + 18x + 9, we calculate f(-3). Since f(-3) = 0, we confirm that x+3x+3 is indeed a factor!

But how do we find all possible rational zeros? For a polynomial like f(x) = x³ - 2x² - 5x + 6, we look at factors in the form ±p/q, where p = factors of the constant term (6), and q = factors of the leading coefficient (1). This gives us ±1, ±2, ±3, ±6 as possible rational zeros.

🔍 Remember: Not all possible rational zeros will actually be zeros, but the actual zeros must be in this list!

Once we've found one zero likef(1)=0like f(1) = 0, we can use synthetic division to divide the polynomial by x1x-1. This gives us a quadratic factor x2x6x² - x - 6 that we can further factor into x3x-3x+2x+2. Our complete factorization is x1x-1x3x-3x+2x+2.

480/81
Days 9
Notes
OBJECTIVES:
1) Identify the possible rational zeros of a polynomial function.
2) Find all the roots of a polynomial func

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Factoring Complex Polynomials

Ready to tackle more challenging polynomials? Let's work through some examples to build your confidence.

For f(x) = 4x³ - 5x² - 23x + 6, we know f(-2) = 0, so x+2x+2 is a factor. Using synthetic division with -2, we get a quadratic expression 4x² - 13x + 3, which factors as 4x14x-1x3x-3. The complete factorization is x+2x+2x3x-34x14x-1.

When working with higher degree polynomials like f(x) = 4x⁴ - 5x³ - 26x² + 9x + 18, start by finding one zero likef(1)=0like f(1) = 0, then use synthetic division repeatedly. This methodical approach breaks down the problem into manageable steps.

🌟 Pro Strategy: After finding one factor, always divide the polynomial by that factor to simplify your work. Keep repeating this process until you reach a quadratic expression that you can factor.

You can handle even challenging polynomials like x³ - 3x² - 16x - 12 by systematically testing possible zeros and using synthetic division. With practice, you'll start to recognize patterns and develop an intuition for finding factors quickly!

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.

Where can I download the Knowunity app?

You can download the app in the Google Play Store and in the Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

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4.9/5

App Store

4.8/5

Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️

Thomas R

iOS user

Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades

Brad T

Android user

Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend

Aubrey

iOS user

Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀

Marco B

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!

Paul T

iOS user