10 Mathematics Quarter 1 - Module 8 FACTORING POLYNOMIALS AND ILLUSTRATING POLYNOMIAL EQUATIONS How I am going to factor polynomials? What is a polynomial equation? (x +4)(x–2) Department of Education ● Republic of the Philippines Mathematics- Grade 10 Alternative Delivery Mode Quarter 1 - Module 8: FACTORING POLYNOMIALS and ILLUSTRATING POLYNOMIAL EQUATIONS Fifth Edition, 2021 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalty. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this book are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education – Division of Bukidnon Development Team of the Module Author/s: Reviewers: Xy-za R. Delfin PhD Cleofe I. Sayta LPT Rhodel A. Lamban, PhD Elbert R. Francisco, PhD Samuel B. Quijardo, PhD Vina Marie B. Latras Photo Artist:: Management Team Chairperson: Co-Chairpersons: Arturo B. Bayocot, PhD CESO III Regional Director Victor G. De Gracia Jr., PhD CESO V Asst. Regional Director Randolph B. Tortola, PhD, CESO IV Schools Division Superintendent Shambaeh A. Usman, PhD Assistant Schools Division Superintendent Mala Epra B. Magnaong, Chief -, CLMD Neil A. Improgo, PhD EPS-LRMS Bienvenido U. Tagolimot, Jr.,PhD EPS-ADM Members Elbert R. Francisco, PhD, Chief -, CID Rhodel A. Lamban, PhD, EPS in Mathematics Rejynne Mary L. Ruiz, PhD, LRMDS Manager Jeny B. Timbal, PDO II Shella O. Bolasco, Division Librarian II Printed in the Philippines by Department of Education – Division of Bukidnon Office Address: Fortich Street, Sumpong, Malaybalay City Telephone: (088) 813-3634 E-mail Address: bukidnon@deped.gov.ph 10 Mathematics Quarter 1 - Module 8 FACTORING POLYNOMIALS and ILLUSTRATING POLYNOMIAL EQUATIONS This instructional material was collaboratively developed and reviewed by educators from public and private schools, colleges, and or/universities. We encourage teachers and other education stakeholders to email their feedback, comments, and recommendations to the Department of Education at bukidnon@deped.gov.ph. We value your feedback and recommendations. DEPARTMENT OF EDUCATION-DIVISION OF BUKIDNON ● REPUBLIC OF THE PHILIPPINES Table of Contents Page COVER PAGE COPYRIGHT PAGE TITLE PAGE TABLE OF CONTENTS OVERVIEW PRE- ASSESSMENT Lesson 1. Factoring Polynomials (Day 1- 4) Pre- Assessment Prior Knowledge Activity 1. Find My Products. Presentation Describing Polynomials Factoring Special Products Factoring Polynomials by Grouping Concept Development Factoring Polynomials with the use of GCF/ monomial factor Factoring Polynomials by using Quadratic Formula Factoring Polynomials by Inspection Factoring Polynomials by AC Method Factoring Special Products Factoring Perfect Square Trinomial Factoring by Grouping Factoring by using Synthetic Division Activities Guided/Controlled Practice: Activity 1. What’s The Other Factor? Independent Practice: Activity 2. Find My Factors. Guided/Controlled Practice: Activity 3. Identify Me. Independent Practice: Activity 4. Find My Special Factors. Activity 5. Fill Me In! Assessment Activity 1. What’s My Pattern? Application Activity 1. Let’s Apply! Activity 2. Complete Me! 6 6 7 10 11 12 13 15 18 19 19 19 19 20 20 20 20 20 20 21 Lesson 2. Illustrating Polynomial Equations (Day 1-2) Pre - Assessment Prior Knowledge Activity 1. Play and Learn! Identifying Several Types of Polynomial Activity 2. What Makes Me True? Presentation Activity 1. Match Me With My Equations. 22 22 23 23 23 24 24 25 Concept Development 1 2 3 3 4 4 4 4 26 Describing Polynomials Writing the Polynomial in Standard Form Activities Guided/Controlled Practice: Activity 1. Math Henyo (Textify Me) Independent Practice: Activity 2. Combine My Parts. Assessment Activity 1. Lead Me to the Formula. Activity 2. Follow My Destiny! Application Activity 1. Make it Real! Activity 2. Construct Me. Independent Assessment: Activity 2. Relate then Connect! Activity 4. Which is Which? POST - ASSESSMENT GENERALIZATION/SYNTHESIS ANSWER KEY REFERENCES 26 27 27 27 28 28 28 29 29 30 30 30 30 32 Overview What comes to your mind when you hear the word(s) polynomials or polynomial equations? Have you ever wondered if you actually use it in a real- life situations? Every activity in this module is uniquely designed to help you show where and when polynomials and polynomial equation are used in the real world. The scope of this module permits it to be used in the new learning situations. The language used recognizes the diverse vocabulary level of students. The lessons and activities are arranged to cater your needs following the standard sequence of the course. The module is divided into two lessons namely: Lesson 1 – Factoring Polynomials Lesson 2 – Illustrating Polynomial Equations After going through this module, you are expected to: Learning Competency 1: factors polynomials (M10AL-Ih-1) (4 days) Sub-tasks: 1. Find the factors of polynomials by using different strategies (by inspection, AC method, Quadratic Formula, Synthetic Division, and by applying the Factor Theorem. 2. Find the factors of the following special products; a. Perfect Square Trinomial b. Difference Between Two Squares c. Sum and Difference of Two Cube Learning Competency 2: illustrates polynomial equations (M10AL-Ii-1) ( 2 days ) Sub-tasks: 1. illustrate, identify and define polynomial equations. 2. solve problems in real-life situation. MATERIALS NEEDED: Algebra Tiles Calculator Video Links References 1 Pre-Assessment Directions: Find out how much you already know about polynomials and polynomial equations. Choose the letter that you think best answers the question. Please answer all items. Take note of the items that you missed to answer correctly and find the right answer as you go through this module. 1. What is the greatest common factor of 20xy2, 16x2y3, and 36x3y4? A. 4xy B. 4xy2 2 3 C. 4x y D. 4x2y2 2. Which of the following is the factored form of x3 + 3x2 – 10x - 24? A. (x + 4) (x -3) (x + 2) B. (x - 4) (x -3) (x + 2) C. (x - 4) (x -3) (x - 2) D. (x + 4) (x + 3) (x - 2) 3. Factor P(x) = x4 + x3 +x2 +x. A. x (x +1)(x2 +1) C. x (1)(x2 +1) B. x (x - 1)(x2 +1) D. x (-1)(x2 +1) 4. Find a cubic polynomial equation with roots -2,2, and 4. A. x3 + 4x2 – 4x + 16 =0 B. 10x3 - x2 – x + 16 =0 C. x3 - 4x2 – x + 16 =0 D. x3 -4x2 – 4x + 16 =0 5. Find the factors of 3x4 + x3 -52x2 -124x -80. A. (x – 2) (x +2) (3x + 4) (x-5) B. (x + 2) (x +2) (3x + 4) (x-5) C. (x – 2) (x -2) (3x + 4) (x-5) D. (x – 2) (x +2) (3x - 4) (x-5) 6. Which of the following represents a polynomial equation? A. x2 – 4 = 0 B. √x +5 = 0 C. y - 2 - 4 = 0 D. x >2 7. Which of the following statements is NOT true about a polynomial? A. It contains a plus or minus sign between each term. B. It contains a constant term or it can be a constant term. C. It contains a variable in the denominator D. It has an exponent or degree. 8. What do you call this equation, x2 + 5x + 3 = 0? A. linear B. monomial C. trinomial D. quadratic 9. What theorem states that any polynomial of degree n has n roots? A. Factor Theorem B. Fundamental Theorem of Algebra C. Rational Root Theorem D. Zero Product Property 10. Which of the following polynomials has a multiplicity of 3 roots? A. (X +2)3 (X-1)2 B. (X +2)2 (X-1) C. (X +2) (X-1) D. X (X +3) If you are done, try to check your pre-assessment. Answer key is provided on page 36 of this module. If you get a perfect score or 8 out of 10 without any help from others, you may skip this module lesson. But, if you missed few items or more than three items you may continue doing all the activities at your own desire. You may submit your rating sheet to your teacher for this pre-assessment. 2 LESSON 1 FACTORING POLYNOMIALS After working on this lesson, you should be able to: 1. find the factors of polynomials by using different strategies such as: a. by Inspection, AC method, Quadratic Formula, Synthetic Division, and Factor Theorem 2. find the factors of the following special products; a. Perfect Square Trinomial b. Difference Between Two Squares c. Sum and Difference of Two Cube Materials needed: Paper, pencil, bond papers/mathematics activity notebook Pre – Assessment Let us find out first what you already know about factoring polynomials. Try to answer all items. Take note of the terms/equations that you were not able to answer correctly and revisit them as you go through this section for selfcorrection. 1. What is the GCF of 5k3p – 3kp2 + k3p5? A. k B. kp C. 3kp D. 5kp 2. Find the factor of 15x2- 5x using the GCF. A. 3x (5x2 – 1) B. 5x (3x2 – 1) C. 3x (5x – 1) D. 5x (3x – 1) 3. Calculate the product of 2x ( b + 5) ( b – 5 ). A. 2bx – 50 B. 2bx – 50x C. 2b2x - 50 D. 2b2x – 50x 4. Which of the following polynomial is NOT factorable? A. x2- 5x + 4 B. x2- 4x + 4 C. x2 + 4x + 4 D. x2 + 2x + 1 5. Decide which of the following is the complete factorization of 12x2 – 8x – 15? A.(4x + 3)(3x – 5) B. (6x - 5)(2x + 3) C. .(6x + 5)(2x – 3) D. cannot be factored Please check if your answers are correct through the Answer Key on page 36. 3 Prior knowledge Factoring is a useful skill in real life. Common applications include: dividing something into equal pieces, exchanging money, comparing prices, understanding time and making calculations during travel. Welcome to factoring polynomials! Before you start learning how to factor polynomials, let’s see what you’ve learned so far when you were in grade 7 to grade 9. This activity will help you understand the lesson. Match the following factors to their product. Activity 1. Find My Product A (Factors) B (Product) 2 a. m -4mn -21n2 1. 2(x-14) 2. 2x (3x2 – 2x + 1) b.x2 -9x +18 3. (x + 4) (x + 3) c. 6x3 - 4x2 + 2x 4. (x - 3) (x – 6) d. x2 + 7x+12 5. (m – 7n) (m + 3n) e. 2x - 28 Well, how was it? Do you think you fared well? Please check your answers if they are correct using the answer key on page __. Did you get a good score? If all your answers are correct, very good! You may still study the module to review what you already know. Who knows, you might learn more new things as well. If you got a low score, don’t feel bad. This only means that this module is right for you. It will help you understand some important concepts that you can apply in your daily life. If you study this module carefully, you will learn the answers to all the items in the test and a lot more! Are you ready? You may now go to the next page to begin Lesson 1. Presentation Polynomials Polynomial expression P(x) is an expression of the form P(x) = 𝒂𝒏 𝒙𝒏 + 𝒂𝒏−𝟏 𝒙𝒏−𝟏 + 𝒂𝒏−𝟐 𝒙𝒏−𝟐 + … + 𝒂𝟎 , where the nonnegative integer n is called degree of polynomial 𝒂𝒏 is the leading coefficient, 𝒂𝟎 is the constant term and coefficients 𝒂𝟎 , 𝒂𝟏,… 𝒂𝒏 are real numbers. We can rewrite polynomial expressions in a simpler form through its factors through factorization or factoring. A factor of polynomial P(x) is any polynomial which divides evenly into P(x). For example, x-5 is a factor of the polynomial x2-25. And the factors of x2-25 are (x-5) (x +5). 4 You have multiple factoring options to choose from when finding the factors of polynomials. The greatest common factor, factoring by inspection, AC method, and the quadratic formula are some of the techniques in finding factors of a polynomial. If the polynomial is a trinomial, you can use the FOIL method for multiplying binomials backward by checking your answer. Factoring Special Products There are some special products that can be used in getting the factors of polynomials by identifying them. Special products are called "special" because they do not need long solutions in finding the factors. These special products can be recognized through their patterns. The different types of special products are perfect square trinomial, difference of two squares, and sum and difference of two cubes. Different Patterns for Special products: 1) Perfect Square Trinomial A2 + 2AB + B2 = (A + B )2 Sum of Squares A2 – 2AB + B2 = (A - B )2 Difference of Squares 2. Difference of Two Squares A2 – B2 = (A + B) (A – B) 3. Sum and Difference of Two Cubes A3 + B3 = (A + B) (A2 - AB+ B2) Sum of Two Cubes A3 - B3 = (A - B) (A2 + AB+ B2) Difference of Two Cubes Factoring Polynomials by Grouping Factoring by grouping is a method of factoring that works on four-term polynomials that have a specific pattern to them. It requires the original polynomial to have a specific pattern that not all four term polynomials will have. If you do the factorization in step three and the two groups don't have a common factor, then you need to go back to square one and try a different approach. Another technique in finding the factors of the polynomials specially if the polynomial is quadratic and the factors are not obvious or factorable, then you can use quadratic formula. Recall in your lesson 1 that the quadratic formula. 𝑥= −𝑏±√𝑏 2 −4𝑎𝑐 2𝑎 Factoring by grouping There’s a factor for every root, and vice versa. The factor theorem states that (x−r) is a factor if and only if r is a root. It implies also that you can go back and forth between the roots of a polynomial and the factors of a polynomial. In other words, if you know one, you know the other. At times, your teacher or your textbook may ask you to factor a polynomial with a degree higher than two. If you can find its roots, you can find its factors. 5 In symbols, the factor theorem states that if x – c is a factor of the polynomial f(x), then f(c) = 0. The variable c is a zero, a root or a solution, whatever you want to call it (the terms all mean the same thing) Concept Development Let’s explore! In this lesson you will use the Greatest Common Factor (GCF), factoring by Inspection, AC method, and quadratic formula in finding the factors of polynomials. GCF is the largest polynomial that will divide evenly into that polynomial. Inspection factoring is just taking the factors of the last term and finding a set of factors that will create a sum of the middle term. And Quadratic Formula is a formula that gives the solutions of the quadratic equation ax2 + bx + c = 0 and that is usually written in the form of 𝑥= −𝑏±√𝑏2 −4𝑎𝑐 2𝑎 . To further understand how to factor polynomials, eight sample problems are provided below with their step-by-step solutions. Study each problem carefully. Let’s Solve the following examples; Example 1: Factor 4x4 - 8x3 Steps Step 1. Arrange the polynomial in descending order. Figure/Expression 4x4 - Arrange the polynomial according to their degree or exponents. 8x3 Step 2. Look for the greatest factor common to every term 4𝑥 4 − 8𝑥 3 Step 3. Divide the polynomial by the factor found in step 1. The quotient is the other factor 4𝑥 4 − 8𝑥 3 Step 4. Express the polynomial as the product of the two factors. 2𝑥 3 2𝑥 3 Discussion = 2𝑥 − 4 Hence the factors of 4x4 - 3x3 = 2𝑥 3 (2𝑥 − 4) 6 Since 2x3 is common to all terms, divide the polynomial by 2x3. 2𝑥 3 (2𝑥 − 4) are factors of 4x4 - 8x3. Check mentally by multiplying the factors using distributive property. Example 2: Factor 6x3 - 4x2+ 2x. Steps Figure/Expression Step 1. Arrange the polynomial in descending order. 6x3 Step 2. Look for the greatest factor common to every term Step 3. Divide the polynomial by the factor found in step 1. The quotient is the other factor Step 4. Express the polynomial as the product of the two factors. - 4x2+ 2x 6𝑥 3 −4𝑥 2 + 2𝑥 2𝑥 6𝑥 3 −4𝑥 2 + 2𝑥 2𝑥 = 3𝑥2 − 2𝑥 + 1 Hence the factors of 6x3 - 4x2+ 2x = 𝟐𝒙 (𝟑𝒙𝟐 − 𝟐𝒙 + 𝟏) Example 3. Factor 3𝑥 2 − 2𝑥 + 1 using quadratic formula. Steps Figure/Expression Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term. Step 3. Use quadratic formula in finding the factors of polynomials. 3𝑥 2 − 2𝑥 + 1 Discussion Write the polynomial in standard form Since 2x is common to all terms, divide the polynomial by 2x. 2𝑥 (3𝑥 2 − 2𝑥 + 1) are factors of 6x3 - 4x2+ 2x Check mentally by multiplying the factors using distributive property. Discussion The polynomial is in descending order There is no GCF. Then transform the 3𝑥 − 2𝑥 + 1 polynomial expression 3𝑥 2 − 2𝑥 + 1 = 0 to polynomial equation. Transform the 3𝑥 2 − 2𝑥 + 1 = 0 expression to From the equation, a =3, b = -2, polynomial equation. c = 1. Substitute in the quadratic formula Then use the quadratic formula since the −𝑏±√𝑏2 −4𝑎𝑐 expression is 𝑥= 2𝑎 quadratic. Find the −(−2)±√(−2)2 −4(3)(−1) roots of quadratic 𝑥= 2(3) expression. X1= 1 and 2 ±√16 x2 = -1/3. 2 𝑥= 𝑥= 6 2 ±√16 6 =2± 4 6 Therefore; 2+4 6 x1 = = =1 ; 6 6 2 − 4 −2 −1 x2 = = = 6 6 3 7 Step 4. Transform the roots to its factors. X1= 1 1( x= 1) x=1 x-1 = 1-1 x-1 = 0 x2 = -1/3 3( x = -1/3) 3x= -1 3x + 1= -1 + 1 3x + 1 = 0 Get the two roots. If one of the roots has a denominator greater than 1, multiply the denominator by it equation to have a factors that is not in fraction form. Then apply addition property of equality. Check by multiplying the factors using FOIL Method. Step 5. Express Hence the factors of the polynomial 3𝑥 2 − 2𝑥 + 1.= (x -1) (3x + 1 ) as the product of the two factors. Note: You can still factor 𝟑𝒙𝟐 − 𝟐𝒙 + 𝟏 by using quadratic formula. 2 −𝑏±√𝑏 −4𝑎𝑐 2𝑎 Use quadratic formula 𝑥 = in finding the factors of ax2 + bx +c when the factors are not obvious and if it is not factorable. Example 4. Factor 2𝑥 2 − 11𝑥 − 21 using quadratic formula. Steps Figure/Expression Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term. Step 3. Use quadratic formula in finding the factors of polynomials. 2𝑥 2 − 11𝑥 − 21 Discussion The polynomial is in descending order 2𝑥 2 − 11𝑥 − 21 2𝑥 2 − 11𝑥 − 21 = 0 There is no GCF. Then transform the polynomial expression to polynomial equation. 2 Transform the expression 2𝑥 − 11𝑥 − 21 = 0 to polynomial equation. From the equation, a =2, b = -11 Then use the quadratic c = -21. Substitute in the quadratic formula formula since the expression is quadratic. −𝑏 ± √𝑏 2 − 4𝑎𝑐 Find the roots of 𝑥= quadratic expression. X1= 2𝑎 7and −(−11) ± √(−11)2 − 4(2)(−21)x2 = -3/2. 2(2) 𝑥= 𝑥= 11 ±√289 2(2) 11 ±17 4 = 11 ± 17 4 11 + 17 28 x1 = = =7 ; 4 4 11 − 17 −6 −3 x2 = = = 4 4 2 8 Step 4. Transform the roots to its factors. X1= 7 1( x= 7) x=7 x-7 = 7-7 x-7 = 0 x2 = -3/2 2( x = -3/2) 2x= -3 2x + 3= -3 + 3 2x + 3 = 0 Step 5. Express Hence the factors of the polynomial 2𝑥 2 − 11𝑥 − 21= (x -7) (2x + 3 as the product of ) the two factors. Get the two roots. If one of the roots has a denominator greater than 1, multiply the denominator by it equation to have a factors that is not in fraction form. Then apply addition property of equality. Check by multiplying the factors using FOIL Method. In continuation of example 2, the factors of 6x3 - 4x2+ 2x are 2x (x -1) (3x + 1). The next technique in finding the factors is factoring through inspection. Sydney made up this riddle for Vince “I’m thinking of two numbers”. The product of the numbers is -24, and the sum of the numbers is -2. Vince tried a few combinations in his head before coming up with the answer: “The numbers must be -6 and +4.” Is any other combination possible? The situation above is an example of finding the factors by inspection. To fully understand let us study example five and six. Example 5. Factor x2 + 3x – 10 using inspection. (x + a)(x + b) = x2 + bx + ax + ab 3x -10 Figure/Expression Steps Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term Step 3. Place the factors for the first term of the trinomial in the front of each set of parentheses. x2 The polynomial is in descending order. + 3x – 10 ( (x + ) Discussion ( ) ) (x - ) There is no GCF. Therefore, the factoring process is begun by opening two sets of parentheses. The factors of the first term x2 is (x) (x). Since the last term is negative, it indicates that they don’t have the same sign. 9 Step 4. Find the factors of the third term. Step 5. Express the polynomial as the product of the two factors. Find the product of Factors of -10 = (5) (-2) -10. (5) (-2) =10. Since the (x + 5) (x - 2 ) middle term is positive 3x, which 2 (x + 5) (x - 2 )= x – 2x + means that the highest factor 5x -10 must be of positive sign and the other factor is negative. Use 3x FOIL Method to get the sum of the outer and inner term, -2x and 5x, must be 3x. Hence the factors of Check by multiplying the factors x2 + 3x – 10 = (x + 5) (x - using FOIL Method. 2 ) Example 6. Factor x2 - 7x – 18 using inspection. (x + a)(x + b) = x2 + bx + ax + ab -7x -18 Figure/Expression Steps Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term Step 3. Place the factors for the first term of the trinomial in the front of each set of parentheses. Step 4. Find the factors of the third term. The polynomial is in descending order x2 - 7x – 18 ( (x + ) ( ) ) (x - ) There is no GCF. Therefore, the factoring process is begun by opening two sets of parentheses. The factors of the first term x2 is (x) (x). Since the last term is negative, it indicates that they don’t have the same sign. Factors of -18 = (-9) (2) (x - 9) (x + 2 ) (x - 9) (x + 2 ) = x2 + 2x – 9x -18 -7x Step 5. Express the polynomial as the product of the two factors. Discussion Hence the factors of x2 - 7x – 18 = (x - 9) (x + 2 ) Find the product of -18. (-9) (2) = -18. Since the middle term is positive 7x, which means that the highest factor must be of negative sign and the other factor is positive. Use FOIL Method to get the sum of the outer and inner term, 2x and -9x, must be -7x. Check by multiplying the factors using FOIL Method. 10 Factoring through inspection is tedious and a long process for some polynomial’s expressions. Thus, alternative way of technique would be very beneficial. Another way of factoring is through grouping or AC method. Closely look at the given steps and compare them with trial and error of factoring by inspection. Example 7. Factor a2 – 7ab + 12b2 using AC method. Steps Figure/Expression Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term a2 – 7ab + 12b2. a2 – 7ab + 12b2. Step 3. Find the product of the leading term and the last term. a2 – 7ab + 12b2. (a2)(12b2) = 12 a2b2 Step 4. Find the factors of 12 a2b2 whose sum is -7ab (-4ab) + (– 3ab) = -7ab The polynomial is in descending order. There is no GCF. Therefore, the factoring process is begun by opening two sets of parentheses. a2 – 7ab + 12b2. (a2)(12b2) = 12a2b2 Step 5. Rewrite the a2 -4ab – 3ab + 12b2 trinomial as a four-term expression by replacing the middle term with the sum of the factors. Step6. Group terms a2 -4ab – 3ab + 12b2 with common factors a (a -4b) – 3b(a - 4b) and get the GCF of the first and second group. Step7. Express the polynomial as the product. Discussion (a -4b) (a -3b) Hence; The factors of a2 – 7ab + 12b2 = (a -4b) (a -3b) 11 (-4a)(-3b) = 12 a2b2 Add the two product the answer is the middle term Replace – 7ab by -4ab – 3ab. a (a -4b) =a2 -4ab -3b(a - 4b) = - 3ab + 12b2 Check mentally by multiplying the factors using distributive property. Factor out the common binomial factor and write the remaining factor as a sum or difference of the common monomial factors. Example 8. Factor 6b2 – 5b - 6 using AC method. Steps Figure/Expression Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term 6b2 The polynomial is in descending order – 5b - 6 6b2 – 5b - 6 Step 3. Find the product of the leading term and the last term. 6b2 – 5b - 6 (6b2)(-6) = -36 b2 Step 4. Find the factors of -36 b2 whose sum is -5b (-9b) + (4b) = -5b Step 5. Rewrite the 6b2 -9b + 4b -6 trinomial as a four-term expression by replacing the middle term with the sum of the factors. Step6. Group terms 6b2 -9b + 4b -6 with common factors 3b (2b -3) + 2 (2b -3) and get the GCF of the first and second group. Step7. Express the polynomial as the product. Discussion (2b - 3) (3b + 2) Hence; The factors of 6b2 – 5b - 6 = (2b - 3) (3b + 2) There is no GCF. Therefore, the factoring process is begun by opening two sets of parentheses. 6b2 – 5b – 6 . (6b2)(-6) = -36 b2 (-9b) (4b) = -36 b2 Add the two product the answer is the middle term Replace – 5b by -9b + 4b. 3b (2b -3) = 6b2 -9b 2 (2b -3) = 4b -6 Check mentally by multiplying the factors using distributive property. Factor out the common binomial factor and write the remaining factor as a sum or difference of the common monomial factors. Perfect Square Trinomial When you square a binomial, the product is called a perfect square trinomial. (x + 4) 2 = (x + 4) (x + 4) = x2 + 8x + 16 square of the 1st term twice the product square of the last term of the two terms In general, polynomials that are perfect square trinomials factor as follows: (x + y)2 = x2+ 2xy + y2 (x– y)2 = x2 – 2xy + y2 Sum of Squares Difference of Squares 12 As we can see the square of the binomial is always a trinomial. When a trinomial is the square of a binomial, we call it a perfect square trinomial. A perfect square trinomial can always be identified because two of its terms are squares, and the remaining term is twice the product of their square roots. The square terms of a perfect square trinomial are always positive. The remaining term may be positive or negative, depending on whether the binomial is the sum or the difference of two numbers. Example 1: Factor x2 - 8x + 16. Steps Step 1. Arrange the polynomial in descending order. Step 2. Look for the greatest factor common to every term Figure/Expression x2 x2 Discussion Write the polynomial in standard form - 8x + 16 - 8x + 16 Step 3. Examine the trinomial x2 – 8x + 16. Get the square root of the first and last term. Then multiply the square root of the first and last term by 2. x2 – 8x + 16 √𝑥 2 = x; √16 = 4, and 2(x)(4) =8x Step 4. Identify the special product Difference of Squares Hence the factors of Factor x2 - 8x + 16 = (x -4 )2 or (x-4) (x-4) Difference of Squares There is no GCF. Therefore the factoring process is begun by opening two sets of parentheses. The first term is a perfect square, the last term is also a perfect square, the middle terms are twice the product of the square root of the first term and the second term and the sign is negative. Check mentally by using the patterns or FOIL method. Example 2: Factor 8x3 + 24x2 + 18x Steps Figure/Expression Step 1. Arrange the polynomial in descending order. 8x3 + 24x2 + 18x Step 2. Look for the greatest factor common to every term 2x (4x2 +12x + 9) 13 Discussion Write the polynomial in standard form Since 2x is common to all terms of 8x3 + 24x2 + 18 Step 3. Examine the trinomial 4x2+12x + 9. Get the square root of the first and last term. Then multiply the square root of the first and last term by 2. Step 4. Identify the special product 4x2+12x + 9 √4𝑥 2 = 2x , √9 = 3, and 2(2x)(3) = 12x and the sign is positive (+). Sum of Squares 4x2 +12x + 9 = (2x + 3) (2x +3) or (2x + 3)2 Hence the factors of 8x3 + 24x2 + 18x = 2x (2x + 3)2 or 2x (2x + 3) (2x +3) The first term is a perfect square, the last term is also a perfect square, the middle terms are twice the product of the square root of the first term and the second term and the sign is positive. Check by using the patterns or FOIL method, the apply the distributive property. Difference of Two Squares The product of the sum and the difference of the same two terms is the difference of two squares. ( x + 9)(x – 9) = (x) 2 – (9) 2 = x2 – 81 square of the 1st term square of the last term x2 – 81 is a difference of two squares. In general, (A- B) (A + B) = A2 – B2, the factors of A2 – B2 are (A- B) (A + B). Let us examine 9y2 - 4. Now √9𝑦 2 = 3y, and √4 = 2. Hence 9y2 - 4= (3y + 2) (3y –2). Example 3: Factor 12h2 -75. Steps Step 1. Arrange the polynomial in descending order. Figure/Expression 12h2 -75 Write the polynomial in standard form. Step 2. Look for the 3 (4h2 – 25) greatest factor common to every term. Step 3. Examine the trinomial 4h2 – 25. Get the square root of the first and last term. Then multiply the square root of the first and last term by 2. Step 4. Identify the special product. Discussion Since 3 is common to all terms of 12h2 -75. 4h2 – 25 √4ℎ2 = 2h √25 = 5, Sum and Difference 4h2 – 25 = (2h -5) (2h + The first term is a perfect square; the last term is also a perfect square. 5) Sum and Difference Hence the factors of 12h2 -75= 3 (2h -5) (2h + 5) or 3 (2h -5)2 14 Check by using the patterns or FOIL method, the apply the distributive property. Sum and Difference of Two Cubes The sum of two cubes has two factors, one binomial and one trinomial. The binomial factor is the sum of the cube roots of the given terms while the trinomial factor is made up the sum of the square of the first term of the binomial factor, the negative of the product of the first and the second terms of the binomial factor, and the square of the second term of the binomial factor. A3 + B3 = (A + B)(A2 – AB + B2) The difference of two cubes has two factors, one binomial and one trinomial. The binomial factor is the difference of the cube roots of the given terms while the trinomial factor is made up the sum of the square of the first term of the binomial factor, the positive of the product of the first and the second terms of the binomial factor, and the square of the second term of the binomial factor. A3 - B3 = (A - B)(A2 + AB + B2) EXAMPLES 4 . Factor a3 + 8. Solution: The given expression can be written as (a)3 + (2)3, by factoring using the pattern A3 + B3 = (A + B) (A2 – AB + B2), we have = (a + 2) (a2 – (a)(2) +22) = (a + 2) (a2 -2a + 4), simplifying further Therefore, the factors of a3 + 8 are (a + 2)(a2 -2a + 4) EXAMPLES 5. Factor 2x4 – 16x Solution: First, look for the greatest factor common to every term. Since 2x is common to all terms, divide the polynomial by 2x. 2x4 – 16x = 2x (x3 - 8).Then factor the difference of two cubes. A3 - B3 = (A - B)(A2 + AB + B2), we have (x3 – 8) = (x - 2) (x2 + (x)(2) +22) = (x - 2) (x2 +2x + 4), simplifying further Therefore, the factors of 2x4 – 16x are 2x (x- 2) (x2 +2x + 4). Example 1: Factor x3 + x2 – x – 1 Steps Figure/Expression Step 1. Arrange the x3 + x2 – x -1 polynomial in descending order. Step 2. Group the first (x3 + x2) + (–x – 1) two terms together and then the last two terms. 15 Discussion Write the polynomial in standard form. Be careful with the negative sign in the second group. (x3 + x2) + (–x – 1) Since the operation now is addition. Step 3. Find the GCF and factor it out. x2(x + 1) – 1(x + 1) Step 4. Factor it out and find the factors of (x2 -1). Step 4. Express the polynomial as the product. (x + 1) (x2 -1) (x + 1)(x + 1)(x – 1), x2(x + 1) = (x3 + x2) and -1 (x +1) = – x -1 x2 – 1 is a difference of squares and factor again. Hence, the factors of x3 + x2 – x – 1 = (x + 1) (x + 1)(x – 1), Check mentally by multiplying the factors Example 2: Factor x3 + x2 - 3x - 3 Steps Figure/Expression Step 1. Arrange the x3 + x2 - 3x - 3 polynomial in descending order. Step 2. Group the first (x3 + x2) + (-3x - 3) two terms together and then the last two terms. Step 3. Find the GCF and factor it out. x2(x + 1) - 3(x + 1) Step 4. Factor it out and find the factors of (x2 - 3). (x + 1) (x2 - 3) From the equation x2 – 3 = 0 , a = 1, Discussion Write the polynomial in standard form. Be careful with the negative sign in the second group. (x3 + x2) + (-3x-3). Since the operation now is addition. x2(x + 1) = (x3 + x2) and - 3(x + 1) = - 3x - 3 Since (x2 - 3) is not factorable. You can use quadratic formula in finding the factors of a quadratic polynomial. b=0 c=3 Substitute in the quadratic formula. 𝑥= −𝑏±√𝑏 2 −4𝑎𝑐 2𝑎 𝑥= 𝑥= 𝑥= −(0)±√(−0)2 −4(1)(−3) 2(1) 0±√12 2 0±2√3 2 =± 2√3 2 𝑥 = ±√3 Therefore, the factors x3 + x2 - 3x - 3 of are (x+1), (x- √𝟑, and (x+ √𝟑) 16 Example 3: Factor 3x3 + 15x2 +2x + 10 Steps Figure/Expression Step 1. Arrange the polynomial in descending order. Step 2. Group the first two terms together and then the last two terms Step 3. Find the GCF and factor it out. 3x3 + 15x2 +2x + 10 Discussion The polynomial is already in order (3x3 + 15x2) + (2x + 10) No need to change the sign since the second group are all positive 3x2 (x + 5) + 2(x + 5) 3x2 (x + 5)= (3x3+15x2) and 2(x + 5) = (2x + 10) 2 Step 4. Factor it out (x + 5) (3x +2) 3x2 +2 is not factorable. and find the factors of You can use quadratic 2 3x +2. formula in finding the factors of a quadratic polynomial. From the equation 3x2 +2 = 0 , a = 3, b=0 c=2 Substitute in the quadratic formula. 𝑥= −𝑏±√𝑏 2 −4𝑎𝑐 2𝑎 𝑥= 𝑥= 𝑥= 𝑥= −(0)±√(−0)2 −4(3)(2) 2(3) 0±√−24 6 0±2√−6 6 √−6 ± 3 =± 2√−6 6 Note that √−1 = 𝑖, an imaginary number, not real Therefore, the factors x3 + x2 - 3x - 3 of are (x+5), (x- √𝟔 𝒊), 𝟑 and (x+ √𝟔 𝒊) 𝟑 Illustrative Examples: Example 1. Find the factors of P(x) where the zeros are 3, -2, -1, and 1. Solution: Applying the zero product property. x= 3 ; x = -2 ; x = -1 ; x =1 (x – 3) =0 (x + 2) = 0 (x – 1)=0 (x + 1)=0 Thus, the factors of P(x) = (x – 3) (x + 2) (x – 1) (x + 1) Example 2. Solve for the other factors of 𝑃(𝑥) = 𝑥 3 − 2𝑥 2 − 3𝑥 + 10, given that (x + 2) is one of its factors. Solution: By Factor Theorem, 𝑥 + 2 is a factor of 𝑥 3 − 2𝑥 2 − 3𝑥 + 10. Then, 𝑥 3 − 2𝑥 2 − 3𝑥 + 10 = (𝑥 + 2) • 𝑄(𝑥) Determine 𝑄(𝑥) using synthetic division. -2 1 -2 -3 10 -2 8 -10 1 -4 5 0 2 𝑄(𝑥) = 𝑥 − 4𝑥 + 5 17 The equation 𝑥 2 − 4𝑥 + 5 = 0 is a depressed equation of 𝑃(𝑥). A depressed equation of P is an equation which has a degree less than that of P. The depressed equation is a quadratic trinomial. Use this to find the other zeros. Since 𝑥 2 − 4𝑥 + 5 is not factorable, use the quadratic formula in finding the values of x. \ Note: A quadratic formula is helpful in finding the roots of ax2 + bx +c if the factors are not obvious or if it is not factorable. From the equation, a = 1, b = -4, Substitute in the quadratic formula. 𝑥= c = 5. −𝑏±√𝑏 2 −4𝑎𝑐 2𝑎 𝑥= 𝑥= 𝑥= −(−4)±√(−4)2 −4(1)(5) 2(1) 4±√16−20 2 4±√−4 2 𝑥 = 4± x1 = 2𝑖 2 = 4± √−4 2 Note that √−1 = 𝑖, an imaginary number, not real 4 + 2𝑖 4 − 2𝑖 = 2 + 𝑖 ; x2 = = 2−𝑖 2 4 The zeros of 𝑃(𝑥) are -2, 2 + 𝑖, and 2 – 𝑖 Thus, 𝑥 3 − 2𝑥 2 − 3𝑥 + 10 = (x + 2) (x – (2 + 𝑖) ) (x + (2 – 𝑖) ) or (x + 2) (x – 2 - 𝑖) (x + 2 – 𝑖) Example 3. Solve for the other zeros of P(x) = 𝑥 4 − 𝑥 3 − 11𝑥 2 + 9𝑥 + 18, given that one zero is -3. Solution: By Factor Theorem, (x + 3) is a factor of 𝑥 4 − 𝑥 3 − 11𝑥 2 + 9𝑥 + 18. Then, 𝑥 4 − 𝑥 3 − 11𝑥 2 + 9𝑥 + 18 = (x + 3) • Q(x). Determine Q(x) using synthetic division, -3 1 -1 -11 9 18 -3 12 -3 -18 1 -4 1 6 0 3 2 Q(x) = 𝑥 − 4𝑥 + 𝑥 + 6. The equation 𝑥 3 − 4𝑥 2 + 𝑥 + 6 = 0 is the first depressed equation of P(x). To find the other zeros, try factors of c in the first depressed equation using synthetic division. For this example, c = 6, the possible factors are {±1, ±2, ±3, ±6}. Try -1, -1 1 -4 1 6 -1 5 -6 1 -5 6 0 So, x + 1 is a factor of 𝑥 3 − 4𝑥 2 + 𝑥 + 6. This implies that 𝑥 3 − 4𝑥 2 + 𝑥 + 6 = (x + 1)(𝑥 2 − 5𝑥 + 6) 18 The equation 𝑥 2 − 5𝑥 + 6 = 0 is the second depressed equation of P(x). There are now two zeros known, -3 and -1. Find the other zeros by factoring the second depressed equation which is a quadratic trinomial. 𝑥 2 − 5𝑥 + 6 = 0 (𝑥 − 2)(𝑥 − 3) = 0 Therefore the zeros of factors of P(x) = 𝑥 4 − 𝑥 3 − 11𝑥 2 + 9𝑥 + 18 (x +1) (x + 3) (x – 2) (x - 3) . Example 4. Solve the other factors of P(x) = 𝑥 3 − 6𝑥 2 − 𝑥 + 30, given that (x + 2) is a factor of the polynomial. Solution: By Factor Theorem, (x - 2) is a factor of 𝑥 3 − 6𝑥 2 − 𝑥 + 30 Then,𝑥 3 − 6𝑥 2 − 𝑥 + 30 = (x + 2) • Q(x). Determine Q(x) using synthetic division, -2 1 -6 -1 30 -2 16 -30 1 -8 15 0 Q(x) = 𝑥 2 − 8𝑥 + 15. The equation 𝑥 2 − 8𝑥 + 15. = 0 is the first depressed equation of P(x). Since 𝑥 2 − 8𝑥 + 15 is a quadratic trinomial. 𝑥 2 − 8𝑥 + 15 = 0 (𝑥 − 3)(𝑥 − 5) = 0 Therefore the factors of P(x) = 𝑥 3 − 6𝑥 2 − 𝑥 + 30 (x +2) (x -3 ) (x – 5) . ACTIVITIES Let’s go beyond Guided/Controlled Practice: ACTIVITY 1. WHAT’S THE OTHER FACTOR? Find the factors of the following polynomial expressions: 1. 2m3y – 12m2y4 = 2m2y (_______) 2. 33w3y2 + 11w2y2 = _____(3w + 1) 3. 9cd4 - 6c2d2 – 3c3d = 3cd (___________) Independent Practice: ACTIVITY 2. FIND MY FACTORS. Find the factors of the following polynomial expressions: 4. x2 + 7x -18 5. 8b2 + 26b + 15 Guided/Controlled Practice: ACTIVITY 1. IDENTIFY ME? Direction: Identify the special products involve. 1. 4z2 – 4z + 1 2. x2 + 12x + 36 3. 16c2 – 64 4. y2 - 81 5. a3 + 125 19 Independent Practice: ACTIVITY 4. FIND MY SPECIAL FACTORS. Direction: Factor each of the following special products. 1. a3 – 125 = (a-5) (_________) 2. 122 - 52 = (12 – 5) (_____) 3. 2x4 -16x = 2x(____) (____) Guided/Controlled Practice: ACTIVITY 5. FILL ME IN! Direction: Find the factors of the following polynomials. A. Find the following factors of P(x) given the following zeros. ( 2points) 1. -2, -3, and 1 = ( x+2) (x +3) (___) 2. -3, -5, and -1 = ( x + 3) ( x + 5) (___) Score 11-15 6-10 1-5 Meaning You have gained complete knowledge on the given exercises. You have gained adequate learning on the given exercises. You can rework on the given exercises. ASSESSMENT Activity 1 What’s My Pattern? A Identify the pattern/s of special products involve: 1) (x – 6)2 = x2 – 12x + 36____________________________________________ 2) (5x + 3y)2 = 25x2 + 30xy + 9y2_______________________________________ 3) (x + 5)(x – 5) = x2 – 25 ____________________________________________ 4) (5m -3) (5m + 3) = 25m2 -9 __________________________________________ 5) (a - 4)(a2 + 4a + 16) = a3 – 64 _______________________________________ It is said that if a polynomial P(x) of degree n, with real coefficients has at most n real roots. Consider the following polynomial equations. At most how many roots does each have? 6. 6x4 - 3x3- 24x2 + 12x = 0_________________________. 7.𝑥 4 − 2𝑥 3 − 7𝑥 2 + 8𝑥 + 12 = 0_____________________ APPLICATION (Performance Tasks) ACTIVITY 1. LET’S APPLY! Answer each of the following completely. 1. If 9x2 + 30x + 25 represent the area of a square, find the binomial that represents the length of a side of the square. 2.One of the roots of the polynomial equation is x4 +4x3 -16x-16 = 0 is -2. Find the other factors 20 Lesson 2 Illustrating Polynomial Equations After going through this module, you should be able to demonstrate understanding of key concepts of polynomial equations, formulate real-life problems involving these concepts and solve those using variety of strategies. Furthermore, you should be able to investigate mathematical relationships in various situations involving polynomial equations. This lesson is good for 2 days. LEARNING OUTCOMES: At the end of the 2 days session, this module will help you: 1. illustrate, identify and define polynomial equations. 2. solve problems in real-life situation. MATERIALS NEEDED: Algebra Tiles, Calculator, Video Links, and References Pre – Assessment Direction: Let us determine how much you already know about polynomial equations. Take this test. Read and understand the questions below. Select the best answer to each item then write your choice on your answer sheet. Do not write anything on this Module. 1. The following represents polynomial equation EXCEPT… A. x 2 – 4x = 0 B. 4x +5 = 0 C. y - 4 = 0 D.√x -½ >2 2. Which of the following equations has three terms? A. x +2 B. (x +1) (x +2) C. x(x2 +2) D. x2(x2 +2) 3. Which of the following does NOT belong to the group? A cubic equation B. linear equation C. quadratic equation D. quadratic inequality 4. . What do you call this equation x2 + 5x + 3 = 0 ? A. binomial B. monomial C. trinomial D. quartic 5 . What theorem states that any polynomial of degree n has n roots? A. Factor Theorem B. Fundamental Theorem of Algebra C. Rational Root Theorem D. Zero Product Property If you are done, try to check your pre-assessment. Answer key is provided on page ___ of this module. If you get a perfect score or 5 out of 5 in the preassessment without any help from others, you may skip this module lesson. But, if you missed few items or more than three items you may continue doing all the activities at your own desire. You may submit your rating sheet to your teacher for this pre-test. 21 Prior knowledge Let us start this lesson by recalling a linear and quadratic equation. The knowledge and skills in doing this activity will help you a lot in understanding the polynomial equation. In going over this lesson, you will be able to identify a polynomial equation and represent it in different ways. ACTIVITY 1. PLAY AND LEARN! STEPS: 1. Choose any number. 2. Multiply your number by a constant 3. 3. Add the sum of your number and 8 to the number you got when you multiplied. 4. Divide by the sum of your number and 2. 5. The answer is always 4. Let’s Try This! 1. 2. 3. 4. Choose 5 Multiply 5 by 3 = 5x3=15 Add (5+8) + 15 =28 Divide 28 by (5+2) =7 Let x=5 x(3) =3x (X+8)+3x = 4x+8 4x+8 the value of x=4 X+2 Did you enjoy the activity? Try another one if you have time, you just follow the steps above. The expression (4x + 8) and (x + 2) at the right of the table describes a polynomial. From the previous modules, you have learned how to derive a polynomial equation by finding the product of two terms or just one term. Fundamental Theorem of Algebra states that any polynomial of degree n has n roots. A polynomial has several types such as: 1. Monomial Equations or Linear Equations An equation which has only one variable term. It can be expressed as ax +b = 0, where a and b are real numbers. Example: 2x + 1= 0 2. Binomial Equations or Quadratic Equations An equation which has only two variable terms. It can be expressed in the algebraic form as ax2 + bx + c = 0. Example: 5x2 + 2x + 1 = 0 3. Trinomial or Cubic Equations An equation which has only three variable terms. Example: x3 + 2x2 + x +4 = 0 4. Quartic Polynomials A polynomial of degree 4. It has also 4 real roots. Example: x4 + x3 + 2x2 + x +4 5. Other polynomials with larger degrees. Example: x20 – 1= 0 22 Observe that the different types presented is in the form of a0 xn + a1 xn-1 +……..+ an-2 x2 + an-1 x + an. Therefore, a polynomial must NOT have the following: a. Negative exponent b. Variable in the denominator c. Fractional exponent Some examples are shown below. Examples 1. x+2 = 0 5 2. x2 + = 0 Polynomial /NOT Polynomial Polynomial NOT Polynomial Reasons Linear Equation It has a variable in the 𝑥 denominator 3. y -3 + y + 2 = 0 NOT Polynomial It has a negative exponent. 4. √x – 5 = 0 NOT Polynomial The exponent of x is ½ 2 5. ½ x - 1 = 0 Polynomial Quadratic/ Binomial Equation You can watch also this video link: www.eHow Education.com// How to describe a polynomial equation for more information. ACTIVITY 2. WHAT MAKES ME TRUE? Directions: Determine whether each expression is a polynomial or NOT. 1. x2 + 2x + 1 = 0 6. ½ x2 - 1 = 0 5 2. 5x3 + 𝑥 = 0 7. ¾ x4 y3 -21x = 0 3. 5x -2 + 5 = 0 8. 9 + √x – 3 = 0 x 4. 10 + 2x + 1 = 0 9. √y + 2 = 0 5. -x2 + 10 = 0 10.¼ x3 + 2x = 0 How did you find the activity? Were you able to describe and illustrate polynomials? If you get a perfect score or 8 out of 10 in this activity without any help from others, you may skip this module lesson. But, if you missed few items or more than three items you may continue doing all the activities at your own desire or try another activity in the next section. Presentation Let’s explore! Based on Mendel’s experiment in genetic breeding, certain traits result from the pairing of two genes, one from the male parent and one from the female. We can use expressions to summarize the possible outcomes of an experiment. For example, suppose a white gumamela flower has a genotype WW, a red gumamela flower has a genotype RR, and a pink gumamela flower has a genotype WR Each letter represent one of two genes that make up the characteristics. The two bred flowers offspring can be expressed using an algebra model called a Punnet square. 23 R PARENT # 1 RW RR WW WR W W R PARENT # 2 The sum of the possible results for four offspring can be written as WW + WR + WR + RR; that is, one white, two pink and one red-gumamela flower. Suppose we substitute x for W and y for R. The result would be a sum of four monomials, xx + xy + xy + yy, or x2 +2xy + y2. The two monomials xy and xy can be combined because they are like terms. Like terms are two monomials that are the same, or differ only by their numerical coefficients. The expression x2 + 2xy + y2 is called a polynomial. A polynomial is a monomial or a sum of monomials. A polynomial must be in the form of a0 xn + a1 xn-1 +……..+ an-2 x2 + an-1 x + an. For more details, refer to this video link: https://MathHelp.com./Solving Polynomial Equations ACTIVITY 1. MATCH ME WITH MY EQUATIONS? Directions. Refer to the previous presentation on types of Polynomial equations in order to answer the following activity. Put the letter of the given equation in the diagram below where you think it belongs. a. X5 -X4 –X + 2 = 0 b. 5X3 + 3X2 –X + 1 = 0 c. ¾ X + 5 = 0 d. 7X3 + 4X -12 = 0 e.-2X3 + 7X – 2 = 0 f. ½ X2 –X + 2 = 0 g. 5X2 –2X + 3 = 0 h. 2X4 - 1 = 0 i. 5X – 3 = 0 j. X20 – 1 = 0 Monomial equation (ax + c = 0) Binomial/quadratic equation (ax2 +bx +c = 0) __________ _________ ________ _______ _______ other polynomials with higher degree ( an-1xn-1+ an-2xn-2 +……) ________ ________ Trinomial/cubic polynomial equation (ax3 + ax2 + ax + c = 0) ___________ __________ _______ 24 Quartic polynomial Equation (ax3+ ax3 + ax2 + ax + c = 0) ________ ________ In the activity you have just done, were you able to identify different types of polynomial equations? Were you able to describe each type? These equations have common characteristics and you will learn more of these in the succeeding activities in the next section. Concept Development Before doing the tasks ahead, read and understand first some important notes on polynomial equations and the examples presented. Enumerate types of polynomial Step 2 Show the formula STEPS Name based on no. of terms Step 1 DISCUSSION A polynomial is one term or the sum or difference of two or more terms. 3x +4 1 linear 2 binomial From the examples, a polynomial can be name by its 2x2+2 2 quadratic 3 Trinomial x+1 /cubic degree and terms. 4x3 3 cubic 1 monomial Recommended link 5 0 constant 1 monomial www.study.com//Forming Polynomial equation with roots Based on the formula a n n-1 2 a0 x + a1 x +……..+ an-2 x + an-1 x polynomial has the following + an. properties: a. NO negative exponent b. NO variable in the denominator c. NO fractional exponent No. of terms DESCRIBING POLYNOMIALS FIGURE/ EXPRESSION/ EQUATION Polynomi al degree Name using degree STEPS FIGURE/ EXPRESSION/ EQUATION Show the TERMS Example1. x3 - 4x+2x2 +7 x3 3 degree 1 degree - 4x 2x2 2 degree 7 0 degree Step 3 Polynomial Standard form Describe examples Example 1. 2x-5 Example 2. 3x4 – 4 + 2x2 Example 3. - 2x +5 - 4x2 + x3 Example 4. 2x + x8 - 1 2x-5 3x4 + 2x2 – 4 x3 - 4x2 - 2x +5 x8 + 2x -1 25 DISCUSSION For a term that has only one variable the. degree of term is the exponent of the variable. The degree of the constant is 0. The degree of the polynomial is the same as the degree of the term with the highest degree. The example in the chart is NOT in standard form. The first example has two terms. which is already in standard form. In the 2nd example, the highest degree is 4. Write it as the first term, then you must interchange the 2nd and 3rd term to have a standard form. Thus, the degree is arranged from highest to lowest. Same process for the examples 3 and 4 STEPS WRITING POLYNOMIAL IN STANDARD FORM Step 1 Identify the number of terms and the highest degree. Step 2 Arrange the terms with degrees from highest to lowest FIGURE/ EXPRESSION/ EQUATION Polynomial Standard form Example 1. 2x-5 2x-5 Example 2. 3x4 – 4 + 2x2 3x4 + 2x2 – 4 Example 3. - 2x +5 - 4x2 + x3 x3 - 4x2 - 2x +5 Example 4. 2x + x8 - 1 x8 + 2x -1 Example 2. 3x4 – 4 + 2x2 2nd term 3rd term interchange Standard form 3x4 + 2x2 – 4 DISCUSSION To transform polynomial into a standard form, identify the number of terms and arrange the degrees in decreasing order. In the first example it has two terms. which is already in standard form. In the 2nd example, the highest degree is 4. Write it as the first term, then you must interchange the 2nd and 3rd term to have a standard form. Thus, the degree is arranged from highest to lowest. Same process for the examples 3 and 4. For more details watch a video link through www. eHowEducation.com// How to describe a polynomial equation. Now that you have a deeper understanding of the topic, you are ready to do the tasks in the next part. Activities Your goal in this section is to take a closer look at some aspects of this topic. You are going to think deeper and test further your understanding of solving problems in polynomials that involve a real life situation. After doing the following activities, you should be able to answer this question: “How do polynomial equations facilitate in solving real-life problems and in making decisions?” You will be given an activity that test if you have understood the previous lesson by performing the tasks leading to the formula of polynomial equation. Guided/Controlled Practice: ACTIVITY 1. Math Henyo (TEXTTIFY ME) 5 points. Direction: CREATE the polynomial illustrated by the statements below. 1. 2. 3. 4. 5. I am a polynomial with three terms written in standard form. The coefficients of my variable x is 1. My constant term is -2. I have two real roots (positive and negative) Create Me! Answer: ______________________________________________ 26 Independent Practice: ACTIVITY 2. COMBINE MY PARTS. (5 points each) Direction: Write a mathematical equation of each from the model below. Given x2 -x2 x -x 1 -1 1._____________________ 2._____________________ 3. _____________________________ Now that you know the important ideas about the topic, lets go deeper by moving to the next section. Assessment Your goal in this section is to apply your learning to real-life situations. You will be given practical task which will demonstrate your understanding of illustrating polynomial equations. ACTIVITY 1. LEAD ME TO THE FORMULA! Directions: Use the situation in the box to answer the questions that follow. Mr. Opalla, one of the farmers in town would like to enclose his rectangular garden whose length is 4 more than twice its width. The area of the garden is 240m2. length (2x + 4) width ( x) A=240m2. 1. How would you represent the length of the garden? A. x B. 2x C. 2x-4 D. 2x+4 2. What mathematical sentence would represent the width of the garden? A. x B. 2x C. 2x-4 D. 2x+4 3. What equation will you use in finding the dimensions of the garden? A. x + (x+4)=240 B. x - (x+4)=240 C. x (x+4)=240 D. x (x+4)=240 4. Which of the following strategies is appropriate in finding the dimensions of the garden? A. Factor Theorem B. Rational Root Theorem C. Fundamental Theorem of Algebra D. Zero Product Property 5. How would you describe the equations formulated from the situation above? A. Linear equation B. Polynomial equation C. Linear inequality D. all of the above 27 In the activity you have just done, were you able to identify and describe polynomial equation and its parts? Was there any point in your life that you realized that you actually use polynomial equations in solving real-life problems and in making right decisions? Before moving to the next section, let us review first the previous lessons. Examples of how to do it is found in the section of Concept Development. ACTIVITY 2. FOLLOW MY DESTINY! Direction: Write the polynomial equation in standard form. POLYNOMIAL STANDARD FORM 1. ½ X2 –X + 2 = 0 1. 2. 3X2 + 5X3 + 3X4–X + 1 = 0 2. 3. 2 X2 + X4 + 4X+1= 0 3. 4. – X2 + 5X -10 = 0 4. 5. 6X-2x2 + 3x4 + 2 = 0 5. ACTIVITY 3. DESCRIBE ME IN MANY WAYS! Direction: Supply the missing word to make the statement true. 1. A _______________ is a monomial or a sum of monomials. 2. The monomials that make up the polynomials are called the _________. 3. The _______________is the sum of the exponents of its leading/first term variables. 4. The degree of the polynomial is the same with the _______________ according to Karl Friedrich Gauss (1777-1895). 5. An equation which has only one variable term is _____________. APPLICATION (Performance Tasks) Have you asked yourself on how an architect was able to divide the space of a building in order to place all amenities the owner’s want? How a carpenter uses minimal materials to fence the rectangular garden? Or how students in Grade 10 identify polynomials by applying the different strategies and theorems? You have learned how to illustrate, describe and define polynomial equation. Your knowledge and skills will be of great help to deepen your understanding for further application of the concepts 28 ACTIVITY 1. MAKE IT REAL! Direction: Refer to the figure below and answer the questions that follow. Questions: 1 1. Suppose the area of square 1 is 4y2 square units and the perimeter of square 2 is 4y, what is the is the area of square 3? __________________ 2 2. If the area of square 3 is 9x2 what is the dimension of square 2? ___________________________ How do you solve a problem? Do you first decide what the problem really is, and take a series of steps to improve the situations? In Algebra, that exactly happens. To solve problems, many people including pharmacists, marine biologists and money managers, all use simple equations and step-by-step methods. You can use polynomial equations and formulas to model a variety of real world problem. ACTIVITY 2. CONSTRUCT ME. Direction: Suppose you were trying to model the product (x + 2) (x + 3). a. Draw a rectangle to represent each type of monomial in the product (5 points). b. Write an example of a polynomial equation / product (5 points). Independent Assessment: ACTIVITY 3 RELATE THEN CONNECT. Directions: Determine whether or Not each expression is a polynomial. Then state the degree. (5 points). Polynomial Expression 1. √𝑥 + 3 = 0 2. X4 -3x3 = 0 Polynomial or NOT Degree Every day you are required to make decisions. Some may be simple as what you want to eat for breakfast or what you should wear to school. Have you ever realized that those quantities can be mathematically represented to come up with practical decisions? ACTIVITY 4. WHICH IS WHICH? Direction: Use mathematical sentences below to answer the questions that follow. 1. 2. 3. 4. 5. 2x2 + 2x + 1 = 0 5 5x4 + 𝑥 = 0 8x -3 + 5 = 0 √y + 2 = 0 –x6 + 7 = 0 6. ½ x3 - 1 = 0 7. X3 + √x – 8 = 0 8. ¼ x -3 = 0 1 9. 𝑥 - 2 = 0 10.X20 – 4 = 0 29 Questions: 1. Which of the given mathematical sentence are polynomial? (3points). ____________________________________________________________ 2. How do you describe polynomial equation? (3points). ____________________________________________________________ 3. Which of the given are NOT polynomial? Why? (3points). ____________________________________________________________ 4. How would you describe those mathematical sentences which are not polynomial equations? (3points). ____________________________________________________________ 5. How are those mathematical sentences which are not polynomial equations different from those equations which are polynomial? (3points). Congratulations! You have finished the activities in lessons 1 and 2. You are a great Learner! Best of luck for the next lesson! Generalization/ Synthesis This lesson was about Factoring Polynomials and Illustrating Polynomial Equations. In Lesson 1, you were able to find the factors of polynomials by using different strategies such as by Inspection, AC method, Quadratic Formula, Synthetic Division, and Factor Theorem. In lesson 2, you were also able to illustrates, identifies, and describes polynomial equations; More importantly, you were given a chance to formulate and solve real-life problems, and demonstrate your understanding of the lesson by doing some practical tasks. You have learned the following: Steps in factoring polynomials: 1.Arrange the polynomial to descending order. 2.Look for greatest common factor. 3.Look for the number of terms in remaining polynomial. If it is four terms use try to use factoring by grouping, if three terms factor into product of two binomials, and if it has two terms use the difference of squares or sum and difference of squares. You can use quadratic formula in finding the factors of quadratic polynomials if the factors are not obvious and not factorable. TYPES OF POLYNOMIAL EQUATION 1. Monomial Equations or Linear Equations An equation which has only one variable term. It can be expressed as ax +b = 0, where a and b are real numbers. Example: 2x + 1= 0 2. Binomial Equations or Quadratic Equations An equation which has only two variable terms. It can be expressed in the algebraic form as ax2 + bx + c = 0. Example: 5x2 + 2x + 1 = 0 30 3. Trinomial or Cubic Equations An equation which has only three variable terms. Example: x3 + 2x2 + x +4 = 0 4. Quartic Polynomials A polynomial of degree 4. It has also 4 real roots. Example: x3 + 2x2 + x +4 5. Other polynomials with or more than 4 degree Example: x20 – 1= 0 LIST OF THEOREMS IN THIS MODULE 1. Fundamental Theorem of Algebra Any polynomial of degree n has n roots. The degree of a polynomial with one variable is the largest exponent of that variable. A polynomial of degree 3 will have 3 roots (places where the polynomial is equal to zero. A polynomial of degree 4 will have 4 roots and soon. 2. Zero Product Property States that if ab = 0, then either a = 0 or b = 0 (or both). A Product of factors is zero if and only if one or more of the factors is zero. 3. Factor Theorem States that a polynomial f(x) has a factor (x-r) if and only if f(r) = 0. Then r is the root. Finding the root is the same as finding the factor of a polynomials It helps us analyze polynomial equations. It tells us how the zeros/roots of a polynomial are related to the factors. It is also helpful in verifying the factors of a certain polynomial expressions/equations. GLOSSARY OF TERMS Degree of a Polynomial- the highest degree of a term in a polynomial Factor Theorem - the polynomial P(x) has x-r as a factor if and only if P(r) =0 Special Products - products that are "special" because they do not need long solutions in finding the factors. It can easily be recognized because of their patterns. Synthetic Division – a short method in dividing polynomial expressions using only the coefficient of the terms. monomial – An expression that is a number, a variable, or the product of a number and one or more variables. Examples: 5c, -a, 17x3, ½x4y3z2 like terms – Are two monomials that are the same or differ only by their numerical coefficients. Examples: xy and xy, x3 and 6x3 equation - A sentence in mathematics that contain an equal sign. Examples: x = 0, 2X-5= 0, 12x3 + 5x2 ˗ 2 = 0 polynomials – A monomial or the sum of monomials. Examples: 12x +4, 3x3 + 2x2 ˗ 2 degree of a polynomial– An exponent in the leading term polynomial equation – An equation of one or more than one term theorem – A statement that needs to be proven. 31 Post Assessment Directions. Let us determine how much you alreay know about factoring polynomials and polynomial equations. Take this test. Read and understand the questions below. Select the best answer to each item then write your choice on your answer sheet. Do not write anything in this Module. 1. Which of the following is the sum and difference of two squares? A. y2 + 24y+ 144 B. 27 - r3 C. b2 + 10b + 24 D. 16c2 - 9 2 2. What are the factors of 3x -x -10? A. (3x + 5) (x - 2) B. (3x + 5) (x + 2) C. (x + 2) (3x-5) D. (3x - 5) (x - 2) 3. Which of the following is TRUE? A. x4 – 4x2y2 + 2y4 = (x + 2y2)2 B. 36x3 + 20xy + 49y2 = (6x + 7)2 C. 100x2 -50xy + 25y2 = (10x -5y)2 D. (x+3) (x + 3) = x2-9 4. What is the greatest common factor of 14x3y, 7x2y, and -7xy? A. 7xy B. -7xy C. 7x2y D. -7x2y 5. Which of the following is the factored form of x3 + 3x2 – 4x - 12? A. (x + 3) (x -2) (x + 2) B. (x + 3) (x + 2) (x + 2) C. (x - 4) (x -3) (x - 2) D. x - 4) (x -3) (x - 2) 6. Which of the following is NOT an example of a polynomial? A. x2 – 4 = 0 B. √x +5 = 0 -2 C. y - 4 = 0 D. x 7. From the equation x3 - 4 x2 + 5x + 3 = 0, what is the highest degree of a polynomial? A. 0 B. 1 C. 2 D. 3 8. Rewrite (x+1) (x+1) in standard form? A. 5(X +2) = 0 B. X(Y-6) = 0 C. (X-3) (X+2) =0 D. X2 + 2X + 1= 0 Given x2 X 1 9. What polynomial is shown by this set? A. 3X2 + 3X + 1= 0 B. 3X2 + 2X + 1= 0 C. 2X2 + 3X + 2=0 D. 2X2 + 2X + 2= 0 10. Which of the following mathematician discovered the relationship between the number of roots which are the same with the number of the degree of a polynomial equation? A. Blaise Pascal B. James Gregory C. Karl Friedrich Gauss D. Rene Descartes If you are done, try to check your posttest. Answer key is provided on page of this module. If you get a perfect score or 8 out of 10 in the post test without any help from others, you are now ready to study the next module. But if you missed few items or more than 5 items you may review all the activities at your own desire. You may submit your rating sheet to your teacher for this post assessment 32 Answer Key PRE- ASSESSMENT (PAGE 2) 1. 2. 3. 4. 5. B D D D C LESSON 1 Pre – Assessment page 3 Prior Knowledge page 4 1. B 2. D 3. D 4. A 5. C 6. A 10. 7. CB 8. D 9. B 10. B ACTIVITIES page 19 Activity 1 What’s the other factor? Activity 2 page 19 Find My Factors . 1. 2m2y(m-y3) 2. 11w2y2(3w+1) 3. 3cd(3d3-2cd-1) 1. e 2. c 3. d 4. b 5. a Activity 3 page 19 Identify Me. Activity 4 page 20 Find My Special Factors 1. Difference of Two Squares 2. Sum of Two Squares 3. Sum and Difference 4.Sum and Difference 5.Sum of Two Cubes 4.(x+9) (x-2) 5 (4b +3) (2b+5) 1.(a-5)(a2 +5a+25) 2.(12-5)(12+5) 3.2x(x-2)(x2+2x+24) Activity 5A page 20 Fill Me In! 1.(x +2)(x+3)(x-1) 2.(x+3)(x+5)(x+1) APPLICATION page 20 Activity 1.Let’s Apply! Complete Me Activity 1B What’s My Pattern? 1.(3x+5)2 6.4 7.4 2. (x+2)(x+2) (x+2) (x-2) X2 + X - 2 1. X2 + 5X - 6 = 0 2. –X2 – 5X + 6 = 0 3. -4X2 + 6X + 3 = 0 Activity 2 page 29 ASSESSMENT page 28 Activity 1.Lead Me to Activity 2 page 29 he Formula Follow My Destiny Activity 3 page 29 Describe Me in Many Ways 1. Polynomial 2. Terms 3. Degree of the polynomials 4. Number of Roots 5. Binomial Equation 1. D 2. C 3. D 4. A 5. B 6. Polynomial 7. Polynomial 8. NOT 9 NOT 10 Polynomial ACTIVITIES page 27 Activity 2.Combine My Parts Monomial Binomial Trinomial c, i f, g b, d , e 1. Polynomial 2. NOT 3. NOT 4. NOT 5. Polynomial ACTIVITIES page 27 Activity 1.Math Henyo Presentation page 25 Match Me With My Equations quartic LESSON 2 Pre – Assessment page 22 Prior Knowledge page 24 Which is Which? other polynomial with higher degrees a, j 1. Difference of Squares 2. Sum of Squares Complete Me 3. Sum and Difference 4.Sum and Difference 5.Difference of Two Cubes h ASSESSMENT page 20 Activity 1A What’s My Pattern? 1. 1/2 X2 - X + 2 = 0 2. 3X4 + 5X3 + 3X2 – X + 1 = 0 3. X4 + 2X2 + 4X + 1 = 0 4. –X2 + 5X – 10 = 0 5. 3X4 – 2X2 + 6X + 2 = 0 1. D 2. A 3. D 4. A 5. B 33 Answer key Application page 30 Activity 3. Relate Then Connect 1. Not ½ Polynomial Application page 30 Activity 2. Construct Me. 2. Application page 30 Activity 1. Make it Real! 4 a. 9X2 b. 1 the exponent of X is b. X2 + 5X + 6 = 0 Application page 30-31 Activity 4 Which is Which? Page 30 X+2 a. X+3 1.D 2.A 3.C 4.A 5.A 1. 1,4,5,6,7,10,11 &15 2. A polynomial is a monomial or a sum of monomials. 3. 2,8,9,12,13 &14 4. Not a polynomial because it has: 1 a variable in the denominator, 2 a fractional exponent, 3 negative exponent 5. Not polynomial equations, cannot be solved by using different theorems mentioned in the module. POST- ASSESSMENT (PAGE 32 6. B 7. D 8. D 9. C 10.A References Deped Instructional Materials That Can be Used As Additional Resources for the Lesson Equations. EASE Modules Year II Modules 1, 2 and 3 BEAM Mathematics 8 Module 4 pp. 1-55 Learners Module for Mathematics 9 pp. 1-113 Learners Module for Mathematics 10 pp. 83-87 References and Website Links Used In This Module References: Department of Education- Instructional Materials Council Secretariat (DepEd-IMCS).2015. Grade 9 Mathematics Learning Module. 2nd ed. Philippines. Rex Book Store INC. Department of Education- Instructional Materials Council Secretariat (DepEdIMCS).2015. Grade 10 Mathematics Learning Module. 2nd ed. Philippines. Rex Book Store INC. Special Products and Factor. Retrieved May 18, 2020. White Crane Education. Retrieved May 25, 2020. Algebra Lab. Retrieved May 20, 2020. 34 Allan E Bellman, et Al. Algebra 2 Prentice Hall Mathematics, Pearson Prentice Hall, New Jersey USA, 2004 Robbie Bonneville, Cindy J. Boyd, Eva Gates, Beatrice Moore-Harris, and Melissa McClure, Algebra 2 (Integration, Applications and Connections). McGraw Hill, Companies Inc., New York, New York, 1998. Website Links for References and for Learning Activities BrownMath.com. Algebra Polynomial solving. (2002). Retrieved May 23, 2020 from http://www.BrownMath.com/Algebra/Polynomial Solving by Stan Brown Paul’s Online Notes.com. Algebra Polynomial Functions, Roots of Polynomial. (2003). https://www.Paul’s Online Notes.com/Algebra/Polynomial Functions/Zeroes/Roots of Polynomial by Paul Dawkins Varsity Tutors.com. Zero Product Property. (2007). https://www.VarsityTutors.com/The Zero Product Property MathIsfun.com. Fundamental Theorem of Algebra. (2017). https://www.MathIsFun.com/Fundamental theorem of Algebra Tutorial.math.lamar.edu.com Zeroes of Polynomials. https://tutorial.math.lamar.edu/classes.com/Alg/zeroesOfPolynomials.aspx Website Links for Videos MathHelp, “Solving Polynomial Equations”October 23, 2007, video, 2:50, https://MathHelp.com./Solving Polynomial Equations, Retrieved May 22, 2020 Brian McLogan, “Finding all the roots of a polynomial:How to find all the roots of a polynomial by factoring December 11, 2015, video, 3:21 http://www.freemathvideos.com/ How to find all the roots of a polynomial by factoring. Retrieved May 22, 2020 For inquiries and feedback, please write or call: Department of Education –Learning Resources Management and Development Center(LRMDC) DepEd Division of Bukidnon Sumpong, Malaybalay City, Bukidnon Telefax: ((08822)855-0048 E-mail Address: bukidnon@deped.gov.ph 35