Unit-2:Polymonials (Core) - New Indian Model School, Dubai
Unit-2:Polymonials (Core) - New Indian Model School, Dubai
Unit-2:Polymonials (Core) - New Indian Model School, Dubai
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CLASS<br />
X<br />
CBSE-i<br />
A L G E B R A ( C O R E )<br />
POLYNOMIALS<br />
UNIT - 2<br />
Shiksha Kendra, 2, Community Centre, Preet Vihar, Delhi-110 092 India
CBSE-i<br />
A L G E B R A ( C O R E )<br />
POLYNOMIALS<br />
UNIT - 2<br />
CLASS-X<br />
Shiksha Kendra, 2, Community Centre, Preet Vihar, Delhi-110 092 India
The CBSE-International is grateful for permission to reproduce and/or<br />
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Preface<br />
The Curriculum initiated by Central Board of Secondary Education -International (CBSE-i) is a progressive step in making<br />
the educational content and methodology more sensitive and responsive to the global needs. It signifies the emergence of a<br />
fresh thought process in imparting a curriculum which would restore the independence of the learner to pursue the<br />
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The CBSE-i aims to carry forward the basic strength of the <strong>Indian</strong> system of education while promoting critical and<br />
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The CBSE has introduced the CBSE-i curriculum in schools affiliated to CBSE at the international level in 2010 and is now<br />
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SEWA (Social Empowerment through Work and Action), Life Skills and Research would be the constituents of this '<strong>Core</strong>'.<br />
The <strong>Core</strong> skills are the most significant aspects of a learner's holistic growth and learning curve.<br />
The International Curriculum has been designed keeping in view the foundations of the National Curricular Framework<br />
(NCF 2005) NCERT and the experience gathered by the Board over the last seven decades in imparting effective learning to<br />
millions of learners, many of whom are now global citizens.<br />
The Board does not interpret this development as an alternative to other curricula existing at the international level, but as<br />
an exercise in providing the much needed <strong>Indian</strong> leadership for global education at the school level. The International<br />
Curriculum would evolve on its own, building on learning experiences inside the classroom over a period of time. The<br />
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their peers through the interactive platforms provided by the Board.<br />
I profusely thank Shri G. Balasubramanian, former Director (Academics), CBSE, Ms. Abha Adams and her team and Dr.<br />
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The CBSE-i website has already started enabling all stakeholders to participate in this initiative through the discussion<br />
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Vineet Joshi<br />
Chairman
Advisory<br />
Shri Vineet Joshi, Chairman, CBSE<br />
Shri Shashi Bhushan, Director(Academic), CBSE<br />
Ideators<br />
English :<br />
Ms. Sarita Manuja<br />
Ms. Renu Anand<br />
Ms. Gayatri Khanna<br />
Ms. P. Rajeshwary<br />
Ms. Neha Sharma<br />
Ms. Sarabjit Kaur<br />
Ms. Ruchika Sachdev<br />
Geography:<br />
Ms. Deepa Kapoor<br />
Ms. Bharti Dave<br />
Ms. Bhagirathi<br />
Ms. Archana Sagar<br />
Ms. Manjari Rattan<br />
Acknowledgements<br />
Mathematics :<br />
Dr. K.P. Chinda<br />
Mr. J.C. Nijhawan<br />
Ms. Rashmi Kathuria<br />
Ms. Reemu Verma<br />
Political Science:<br />
Ms. Sharmila Bakshi<br />
Ms. Srelekha Mukherjee<br />
Conceptual Framework<br />
Shri G. Balasubramanian, Former Director (Acad), CBSE<br />
Ms. Abha Adams, Consultant, Step-by-Step <strong>School</strong>, Noida<br />
Dr. Sadhana Parashar, Head (I & R),CBSE<br />
Ms. Aditi Misra Ms. Anuradha Sen Ms. Jaishree Srivastava Dr. Rajesh Hassija<br />
Ms. Amita Mishra Ms. Archana Sagar Dr. Kamla Menon Ms. Rupa Chakravarty<br />
Ms. Anita Sharma Ms. Geeta Varshney Dr. Meena Dhami Ms. Sarita Manuja<br />
Ms. Anita Makkar Ms. Guneet Ohri Ms. Neelima Sharma Ms. Seema Rawat<br />
Dr. Anju Srivastava Dr. Indu Khetrapal Dr. N. K. Sehgal Dr. Uma Chaudhry<br />
Material Production Groups: Classes IX-X<br />
Science :<br />
Ms. Charu Maini<br />
Ms. S. Anjum<br />
Ms. Meenambika Menon<br />
Ms. Novita Chopra<br />
Ms. Neeta Rastogi<br />
Ms. Pooja Sareen<br />
Economics:<br />
Ms. Mridula Pant<br />
Mr. Pankaj Bhanwani<br />
Ms. Ambica Gulati<br />
Material Production Groups: Classes VI-VIII<br />
History :<br />
Ms. Jayshree Srivastava<br />
Ms. M. Bose<br />
Ms. A. Venkatachalam<br />
Ms. Smita Bhattacharya<br />
English :<br />
Science :<br />
Mathematics :<br />
Geography:<br />
Ms. Rachna Pandit<br />
Dr. Meena Dhami<br />
Ms. Seema Rawat<br />
Ms. Suparna Sharma<br />
Ms. Neha Sharma<br />
Mr. Saroj Kumar<br />
Ms. N. Vidya<br />
Ms. Leela Grewal<br />
Ms. Sonia Jain<br />
Ms. Rashmi Ramsinghaney<br />
Ms. Mamta Goyal<br />
History :<br />
Ms. Dipinder Kaur<br />
Ms. Seema kapoor<br />
Ms. Chhavi Raheja<br />
Ms. Leeza Dutta<br />
Ms. Sarita Ahuja<br />
Ms. Priyanka Sen<br />
Political Science:<br />
Ms. Kalpana Pant<br />
Dr. Kavita Khanna<br />
Ms. Kanu Chopra<br />
Ms. Keya Gupta<br />
Ms. Shilpi Anand<br />
Coordinators:<br />
Dr. Sadhana Parashar, Ms. Sugandh Sharma, Dr. Srijata Das, Dr. Rashmi Sethi,<br />
Head (I and R) E O (Com) E O (Maths) E O (Science)<br />
Shri R. P. Sharma, Consultant Ms. Ritu Narang, RO (Innovation) Ms. Sindhu Saxena, R O (Tech) Shri Al Hilal Ahmed, AEO<br />
Ms. Seema Lakra, S O<br />
Material Production Group: Classes I-V<br />
Dr. Indu Khetarpal Ms. Rupa Chakravarty Ms. Anita Makkar Ms. Nandita Mathur<br />
Ms. Vandana Kumar Ms. Anuradha Mathur Ms. Kalpana Mattoo Ms. Seema Chowdhary<br />
Ms. Anju Chauhan Ms. Savinder Kaur Rooprai Ms. Monika Thakur Ms. Ruba Chakarvarty<br />
Ms. Deepti Verma Ms. Seema Choudhary Mr. Bijo Thomas Ms. Mahua Bhattacharya<br />
Ms. Ritu Batra<br />
Ms. Kalyani Voleti<br />
Ms. Preeti Hans, Proof Reader
Content<br />
1. Syllabus 1<br />
2. Scope Document 2<br />
3. Material Resource 5<br />
• 2.1 Introduction of <strong>Unit</strong> 5<br />
• 2.2 Value of a Polynomial at a point 7<br />
• 2.3 Zero of a Polynomial 7<br />
• 2.4 Relation between zeroes and coefficients 10<br />
• 2.5 Geometrical representation of zeroes of polynomial 12<br />
• 2.6 Reading zeroes of linear and quadratic polynomial from graph 16<br />
• 2.7 Division of Polynomials 18<br />
4. Teacher's Support Material 21<br />
• 2.8 Activity 1 - Warm up (W1) 22<br />
• 2.9 Activity 2 - Warm up (W2) 24<br />
• 2.10 Activity 3 - Pre Content (P1) 26<br />
• 2.11 Activity 4 - Content Worksheet (CW1) 26<br />
• 2.12 Activity 5 - Content Worksheet (CW2) 27<br />
• 2.13 Activity 6 - Content Worksheet (CW3) 27<br />
• 2.14 Activity 7 - Content Worksheet (CW4) 28<br />
• 2.15 Activity 8 - Content Worksheet (CW5) 28<br />
• 2.16 List of useful resources 29
Content<br />
5. Students' Support Material 31<br />
• Worksheet 1 - Warm up (W1 & W2) 32<br />
• Self assessment Rubric 1 34<br />
• Worksheet 2 - Pre Content (P1) 35<br />
• Worksheet 3 - Self assessment Rubric 2 36<br />
• Worksheet 4 - Content (CW1) 37<br />
• Worksheet 5 - Self assessment Rubric 3 39<br />
• Worksheet 6 - Content (CW2) 40<br />
• Worksheet 7 - Self assessment Rubric 4 41<br />
• Worksheet 8 - Content (CW3) 42<br />
• Worksheet 9 - Self assessment Rubric 5 44<br />
• Worksheet 10 - Content (CW4) 45<br />
• Worksheet 11 - Self assessment Rubric 6 47<br />
• Worksheet 12 - Content (CW5) 48<br />
• Worksheet 13 - Self assessment Rubric 7<br />
49<br />
• Worksheet 14 - Post Content (PCW1) 50<br />
• Worksheet 15 - Post Content (PCW2) 51<br />
6. Assessment Guidance Plan 53
SYLLABUS UNIT 2 :<br />
ALGEBRA (CORE)-POLYNOMIALS<br />
Polynomial<br />
Zeroes of polynomial<br />
Division algorithm<br />
Recapitulation of vocabulary of polynomials<br />
in one variable - coefficient, terms, degree,<br />
constant, linear, quadratic, cubic polynomial<br />
Zero of linear polynomial, zeroes of quadratic<br />
polynomial, finding zeroes of polynomial by<br />
splitting middle terms, relation between<br />
zeroes and coefficients. Geometrical<br />
representation of zeroes of polynomial,<br />
reading zeroes of linear and quadratic<br />
polynomial from graph.<br />
Dividend= divisor x quotient + remainder<br />
Division of quadratic polynomial by linear<br />
polynomial<br />
Division of cubic polynomial by linear<br />
polynomial<br />
Division of cubic polynomial by quadratic<br />
polynomial<br />
MATHEMATICS UNIT - 2<br />
1
SCOPE DOCUMENT<br />
Key terms<br />
1. Zeroes of a polynomial<br />
2. Cubic polynomial<br />
3. Division algorithm<br />
Learning Objectives<br />
1. To tell the possible number of zeroes for a given polynomial.<br />
2. To find zero of a linear polynomial algebraically.<br />
3. To find zeroes of a quadratic polynomial algebraically.<br />
4. To find zeroes of a cubic polynomial algebraically.<br />
5. To understand the geometrical meaning of zeroes.<br />
6. To read the zeroes of a polynomial from given graph.<br />
7. To find the polynomial when zeroes are known.<br />
8. To divide the linear polynomial by a linear polynomial.<br />
9. To divide the quadratic polynomial by a linear polynomial.<br />
10. To divide the cubic polynomial by a linear polynomial.<br />
11. To divide the cubic polynomial by a quadratic polynomial.<br />
12. To express the division of two polynomials using division algorithm<br />
2<br />
MATHEMATICS UNIT - 2
Extension Activities:<br />
Finance<br />
1. Find the zeroes of a cubic polynomial by the method of grouping.<br />
2. Find the zeroes of a bi-quadratic polynomial using division.<br />
Cross Curricular Links : Polynomials define simple curves in the language of mathematics so<br />
that they may be easily analyzed and modified. Simple curves can be combined to closely<br />
approximate more complicated curves. Planets, weather etc. move in curves. Mechanical<br />
forces, chemical and biological processes, etc. are not constant but change over space and time.<br />
These changes and other changes like fluctuations in the economy can be approximated by<br />
curves. Also, televisions, computers, phones, music players, etc. all receive signals that are<br />
sine waves (curves). Polynomials are the building blocks of all these sciences.<br />
Assessment of present value is used in loan calculations and company valuation. It involves<br />
polynomials that back interest accumulation out of future liquid transactions, with the aim of<br />
finding an equivalent liquid (present, cash, or in-hand) value. Tax and economic calculations<br />
can usually be written as polynomials as well.<br />
Electronics<br />
Electronics use many polynomials. The definition of resistance, V=IR, is a polynomial relating<br />
the resistance from a resistor to the current through it and the potential drop across it.<br />
Curve Fitting<br />
Polynomials are fit to data points in both regression and interpolation. In regression, a large<br />
number of data points is fit with a function, usually a line: y=mx+b. The equation may have<br />
more than one "x" (more than one dependent variable), which is called multiple linear.<br />
In interpolation, short polynomials are joined tegether so they pass through all the data points.<br />
For those who are curious to research this more, the name of some of the polynomials used for<br />
interpolation are called "Lagrange polynomials", "cubic splines" and "Bezier splines".<br />
Chemistry<br />
Polynomials come up often in chemistry. Gas equations relating diagnostic parameters can<br />
usually be written as polynomials, such as the ideal gas law: PV=nRT (where 'n' is mole count<br />
and 'R' is a proportionality constant).<br />
MATHEMATICS UNIT - 2<br />
3
Formulas of molecules in concentration at equilibrium also can be written as polynomials. For<br />
example, if A, B and C are the concentrations in solution of OH-, H2O+, and H2O respectively,<br />
then the equilibrium concentration equation can be written in terms of the corresponding<br />
equilibrium constant K: KC=AB.<br />
Physics and Engineering<br />
Physics and engineering are fundamentally studies in proportionality. If a stress is increased,<br />
how much does the beam deflect? If a trajectory is fired at a certain angle, how far away will it<br />
land?<br />
Polynomials are really useful in calculating projectile paths as the physics equation for<br />
projectile motion is:<br />
s=ut + 0.5 at ²<br />
this is a quadratic<br />
Other polynomials can be derived (calculus) to find the rate of change.<br />
Such as if you have a distance time graph, d (t) = t² + 5 for example, you can find the velocity of<br />
that graph at any point in time.<br />
Read more :<br />
How are Polynomials used in Life? |eHow.com<br />
http://www.ehow.com/about_5479798_polynomials-used-life.html#ixzz1Inv2GL6n<br />
4<br />
MATHEMATICS UNIT - 2
2.1 Introduction of the unit:<br />
In previous Classes you have studied about the polynomials. Let us recall all<br />
concepts learnt.<br />
Polynomial is an algebraic expression in one variable, say x .It is the sum of two or<br />
n<br />
more terms of the form ax , where a is real number and x is a non negative integer.<br />
Polynomial can be written in the form<br />
2 n-2 n-1 n<br />
a<br />
0<br />
+ a1x + a2x + .....................+ an-2x + an-1x + a<br />
n<br />
x<br />
where a , a , a ,.......a , a , a are real number and are known as coefficients and are<br />
0 1 2 n-2 n-1 n<br />
known as non-negative integers.<br />
Some examples of polynomial are<br />
2 8 2 3 2<br />
x +5x+6, x +8x +15x+9, x +2x +x+4<br />
7 The coefficient of highest power term is known as leading coefficient.<br />
8 The coefficient of a term with power 0 is called a constant,<br />
3<br />
In 3x +5x+7. 7 is a constant and 3 is the leading coefficient.<br />
Let us revise these terms.<br />
What is a monomial? Polynomial with one term is known as monomial<br />
Examples of monomials are<br />
5 3<br />
15, 24x, 12y , -100m<br />
MATERIAL RESOURCES<br />
What is a binomial? Polynomial with two terms is known as binomial<br />
Examples of binomials are<br />
• 16y² + 25y<br />
• -112x³ - 23x<br />
• 31x + 5x²<br />
MATHEMATICS UNIT - 2<br />
5
What is a trinomial? A trinomial is a polynomial with three terms<br />
Examples of trinomials are:<br />
2<br />
• 5x + 6x + 7<br />
3 2<br />
• -12x + 63x - 25x<br />
Degree of a Polynomial<br />
Power of variable in each term is known as degree of that term. For example for a<br />
3 2<br />
polynomial p(x) = 2x + 5x +7 x+ 6<br />
Term<br />
Degree of corresponding term<br />
3<br />
2x 3<br />
2<br />
5x 2<br />
7 x 1<br />
6 0<br />
The term with highest power determines the degree of a polynomial .In the above<br />
case the highest power is 3. So the degree of the polynomial is 3.<br />
If p(x) is a polynomial in x, the highest power of x in p(x) is called the degree of the<br />
polynomial p(x).Depending on the degree, a polynomials can be named as:<br />
Linear Polynomial: A polynomial whose degree is 1.<br />
Quadratic Polynomial: A polynomial whose degree is 2.<br />
Cubic Polynomial: A polynomial whose degree is 3.<br />
Degree Name Example<br />
0 constant 10<br />
1 linear 5x+2<br />
2 quadratic 5x² + 14x + 6<br />
3 cubic 12x³ + 3x + 7<br />
4 2<br />
4 quartic 30x + 2x + 24<br />
5<br />
5 quintic 2x + 3x + 1<br />
6<br />
MATHEMATICS UNIT - 2
2.2 Value of a polynomial at a point<br />
2<br />
Consider the polynomial p(x) = x + 5x - 3. When we put x = 1 in p(x), then we get<br />
2<br />
p(1) = 1 +5 × 1 - 3 = 3. The value '3', obtained by replacing x by 1 in p(x), is the value of<br />
given polynomial at x = 1.<br />
Now, consider p(x) = 5x+3<br />
p(0) = 5(0) +3 = 3<br />
p(1) = 5(1) +3 = 8<br />
p(2) = 5(2) +3 = 13<br />
In general, If p(x) is a polynomial in x, and if k is any real number, then the value<br />
obtained by replacing x by k in p(x), is called the value of p(x) at x = k, and is denoted by<br />
p(k).<br />
3 2<br />
What is the value of p(x) = 5x -3x -4x+1 at x= -3?<br />
3 2<br />
p(x) = 5x -3x -4x+1<br />
3 2<br />
p(-3)= 5(-3) -3(-3) -4(-3)+1<br />
Simplify and get the answer.<br />
2.3 Zero of a Polynomial<br />
In class 9 students have learnt the concept of finding zero of a linear polynomial.<br />
Definition:<br />
Zero of a polynomial is that value of x that makes the polynomial equal to 0. In other<br />
words, the number r is a zero of a polynomial P(x) if and only if P(r) = 0.<br />
Example 1: Consider a linear polynomial 5x + 7,<br />
To get its zero, we have to find the value of x, so that it becomes zero.<br />
Therefore 5x + 7 = 0<br />
⇒x = - 7/5<br />
Exercise: Find the zero of following linear polynomials:<br />
1. P(x) = 4x -3<br />
MATHEMATICS UNIT - 2<br />
7
2. Q(x) = 7x + 5/3<br />
3. R(t) = 9t- 4<br />
4. P(x) = 14x + 5<br />
2<br />
Example 2: Consider a quadratic polynomial x -5x+6,<br />
To get its zero, we have to find the value of x, so that it becomes zero.<br />
2<br />
⇒x -5x+6 = 0<br />
2<br />
⇒x -3x-2x+6 = 0<br />
⇒x(x-3) -2 (x-3) = 0<br />
⇒(x-3)(x-2) = 0<br />
⇒x = 3 or x= 2<br />
2.3.1 How many zeroes can a polynomial have?<br />
Number of zeroes of a polynomial depends on its degree. A polynomial of degree n can<br />
have at the most n number of zeroes.<br />
A polynomial of degree two can have at the most two zeroes.<br />
2<br />
Polynomial x + 2x +1 has only one zero i.e. -1.<br />
2<br />
Polynomial x + 3x+2 has two zeroes -1 and -2.<br />
A polynomial of degree 3 can have at the most three zeroes.<br />
Can you write a polynomial of degree three with one zero?<br />
Can you write a polynomial of degree three with two zeroes?<br />
Can you write a polynomial of degree three with three zeroes?<br />
It is possible to write a polynomial when the zeroes are known.<br />
To write a polynomial when its zeroes are known<br />
In the example 2 given above you may observe that 2 and 3 are zeroes of polynomial and<br />
x-2 and x-3 are factors of a given polynomial.<br />
8<br />
MATHEMATICS UNIT - 2
If a given polynomial p(x) can be factorised and can be written as (x-a) (x-b) (x-c)…..<br />
then the polynomial will become zero if any one of its factor is zero.<br />
Thus we can say that if a polynomial has zeroes as a and b , it will have factors as x-a and<br />
2<br />
x-b, then the polynomial will be (x-a)(x-b)=x -(a+b)x +ab.<br />
Example 3: Find a polynomial of degree 3 with zeroes as -2,1,3.<br />
Solution: If -2 is a zero of a polynomial then x+2 is a factor of polynomial. Similarly<br />
other factors are x-1 and x-3.Therefore polynomial is (x+2) (x-1) (x-3).<br />
3 2<br />
Simplify to get the required polynomial p(x)= x -2x -5x +6<br />
2.3.2 Finding zeroes of a polynomial using constant term and leading<br />
coefficient<br />
2<br />
Consider the polynomial q(x)=x - 6x +5.<br />
Here the constant term is 5.Its factor are say p=1 and 5.<br />
Here the leading coefficient is 1.its only factor is say q= 1.<br />
Divide the factors of the constant by the factors of leading coefficient i.e. find p/q. Take<br />
positive and negative values of p/q. Here 1,-1 and 5,-5 are obtained.<br />
Insert the numbers obtained in the polynomial,<br />
2<br />
Q (1) = (1) -6(1) +5=0<br />
2<br />
Q (5) = (5) - 6(5) +5 =0<br />
2<br />
Q (-1) = (-1) -6(-1) +5≠0<br />
2<br />
Q (-5) = (-5) -6(-5) +5≠0<br />
You may observe that 1 and 5 are zeroes of given polynomial.<br />
Note : Zeroes obtained in this manner are known as Rational Zeroes.<br />
3<br />
Examples 4: Find the roots of x -3x +2=0<br />
Solution: Here leading coefficient= 1.Its factors are q=1<br />
Constant term= 2. Its factors are p = 1 and 2<br />
So, p/q= 1 and 2<br />
MATHEMATICS UNIT - 2<br />
9
Take both positive and negative values of p/q=1,-1,2,-2<br />
3<br />
P(1)= (1) - 3(1)2 +2=0<br />
3<br />
P(-1)= (-1) - 3(-1)2 +2≠0<br />
3<br />
P(2)= (2) - 3(2)2 +2≠0<br />
3 2<br />
P(-2)= (-2) - 3(-2) +2≠0<br />
Therefore x=1 is a zero of the given polynomial. But the given polynomial is of degree 3,<br />
so it can have at the most three zeroes. From above method we are able to find only one<br />
zero. Other two zeroes in this case can be determined by dividing the given polynomial<br />
by x-1 as x-1 is one of the factors of given polynomial.<br />
We will first learn the division algorithm and then will learn further to find all zeroes of<br />
cubic polynomial.<br />
Example 5. Let P(x) = 5x³ - 4x² + 7x - 8. Find P (1).What do you conclude about the<br />
factors of P(x)?<br />
2.4 Relationship between zeroes and coefficients of a quadratic polynomial<br />
What is a quadratic polynomial?<br />
2<br />
A polynomial ax +bx+c, a ≠0, a, b, c, are real numbers is called a quadratic polynomial.<br />
Consider a quadratic polynomial 5x²+ 6x +1. To get its zero, we write 5x²+ 6x +1 = 0. This<br />
means we have to find the value (s) of the variable x which makes the given expression<br />
0.<br />
By splitting the middle term, we get 5x²+ 5 x +x +1 = 0.<br />
This means, 5x(x+1) + 1(x+1) = 0<br />
⇒(5x+1)(x+1) = 0<br />
⇒x = -1/5 or x = -1<br />
Therefore, the two zeroes are -1/5 and -1<br />
Now, find the sum of zeroes and product of zeroes<br />
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MATHEMATICS UNIT - 2
Sum of zeroes =<br />
- 1 5 -1= - 6 5<br />
Observe the coefficient of x and the coefficient of x² terms.<br />
We find that Sum of zeroes = -<br />
Coefficient of x<br />
coefficient of x²<br />
Now, find the product of zeroes<br />
Product of zeroes =<br />
- 1 5 x -1= 1 5<br />
2<br />
Observe the constant term and the coefficient of x terms.<br />
We find that Product of zeroes =<br />
Coefficient term<br />
coefficient of x²<br />
In a quadratic polynomial ax²+bx+c, a 0, a, b, c, are real numbers<br />
Sum of zeroes = -<br />
Product of zeroes =<br />
Coefficient of x<br />
coefficient of x²<br />
Coefficient term<br />
coefficient of x²<br />
Example: Consider a quadratic polynomial 2x²-8x + 6<br />
By splitting the middle term we get,<br />
2x²-8x+6 = (2x-2)(x-3)<br />
= 2(x-1)(x-3)<br />
Zeroes of this polynomial are given by x-1=0 and x-3=0<br />
x=1 and x=3<br />
Sum of zeroes = 1+3 = 4 = -(-8)/2 = -<br />
Coefficient of x<br />
coefficient of x²<br />
Product of zeroes =( 1) (3) = 3 = 6/2 =<br />
Coefficient term<br />
coefficient of x²<br />
MATHEMATICS UNIT - 2<br />
11
Now, let us learn to write a quadratic polynomial when sum and product of its zeroes is<br />
given.<br />
Remember: A quadratic polynomial whose sum of zeroes is S and product of zeroes is P<br />
is given by x² -Sx +P<br />
Example: Write a quadratic polynomial whose sum of zeroes is 5 and product of zeroes<br />
is 10<br />
Here Sum of zeroes = 5 and Product of zeroes= 10<br />
Using the formula, required polynomial is x² - 5x + 10<br />
Note: If αand βare zeroes of a quadratic polynomial then the required polynomial is<br />
given by (x- α) (x- β)<br />
2.5 Geometric Representation of Zero of a Polynomial<br />
What are the x-intercept and y-intercept of a graph?<br />
(0,b)<br />
y-intercept<br />
(-a, 0)<br />
x-intercept<br />
The x-intercept is that value of x where the graph crosses or touches the x-axis. At the x-<br />
intercept on the x-axis y = 0.<br />
The y-intercept is that value of y where the graph crosses the y-axis. At the y-intercept,<br />
x = 0.<br />
What is the relationship between the zero of a polynomial and the x-intercepts of its<br />
graph?<br />
The zeroes are the x-intercepts!<br />
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The zeroes of x² - x - 6 are -2 and 3. Therefore, the graph of y = x² - x - 6 will cross the<br />
x - axis at -2 and 3.<br />
The graph of a linear polynomial of the form ax + b, a not equal to zero is a straight line<br />
which intersects the x-axis at exactly one point. The value of x coordinates of the point<br />
where the line meets x- axis is zero of the polynomial.<br />
Graph of a linear Polynomials<br />
Consider the following graph<br />
MATHEMATICS UNIT - 2<br />
13
This is a graph of linear polynomial 2x+3. It intersects the x-axis at point (-1.5, 0).<br />
So, the linear polynomial 2x+3 has one zero, given by -1.5 (x-coordinate of point where<br />
line cuts the x-axis)<br />
Exploring graphs of Quadratic polynomial<br />
2<br />
• A quadratic polynomial is given by ax +bx+c, a ≠0, a,b,c, are real numbers.<br />
• The degree of a quadratic polynomial is 2.<br />
• Graph of a quadratic polynomial is a parabola.<br />
• There are at most two zeroes of a quadratic polynomial.<br />
Observe the following graphs.<br />
This is a graph of a quadratic polynomial which do not intersect the x- axis at any of the<br />
points, so there is no zero of this polynomial.<br />
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In the second graph, the curve touches the x-axis at one point, so it has 1 zero. What is<br />
that zero?<br />
In the following graph, the curve cuts the x-axis at two points, so the given quadratic<br />
polynomial has two zeroes. Write the two zeroes from the graph.<br />
Note: The zero of a quadratic polynomial is the value of x- coordinate of a<br />
point where the graph of the polynomial cuts the x-axis. It has at most 2 zeroes<br />
MATHEMATICS UNIT - 2<br />
15
2.6 Observing the number of zeroes of a polynomial from its graph<br />
(i)<br />
The graphs of y = p(x) are given in following figure, for some polynomials p(x). Find the<br />
number of zeroes of p(x), in each case.<br />
(ii)<br />
Observation: The graph of y=p(x) does not intersect the x-axis at any point. This means<br />
it has no zero.<br />
(iii)<br />
Observation: The graph of y=p(x) intersects the x-axis at one point. This means it has<br />
one zero.<br />
Observation: The graph of y=p(x) intersect the x-axis at three points. This means it has 3<br />
zeros.<br />
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MATHEMATICS UNIT - 2
(iv)<br />
Observation: The graph of y=p(x) intersect the x-axis at two points. This means it has 2<br />
zeros.<br />
(v)<br />
Observation: The graph of y=p(x) intersect the x-axis at four points. This means it has 4<br />
zeros.<br />
(vi)<br />
Observation: The graph of y=p(x) intersect the x-axis at three points. This means it has 3<br />
zeros.<br />
MATHEMATICS UNIT - 2<br />
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2.7 Division of polynomials<br />
In previous classes students have learnt the division of integers. Also, they have the<br />
knowledge of Euclid's division lemma i.e. dividend = divisor x quotient + remainder.<br />
Let us see the process of division of polynomials.<br />
First let us divide 5x³ - x³ + 6 by x - 4.<br />
We write it as shown below<br />
x - 4 5x³ - x² + 0x + 6<br />
We need to have the terms written down with the exponents in decreasing order and to<br />
make sure we don't make any mistakes we add in any missing terms with a zero<br />
coefficient.<br />
Now we we need to multiply x - 4 to get the first term in first polynomial. In this case<br />
that is 5x². So multiply x - 4 by 5x² and subtract the results from the first polynomial.<br />
5x²<br />
x - 4 5x³ - x² + 0x + 6<br />
- (5x³ - 20x²)<br />
19x² + 0x + 6<br />
The new polynomial is called the remainder. We continue the process until the degree<br />
of the remainder is less than the degree of the divisor, which is x - 4 in this case. So, we<br />
need to continue until the degree of the remainder is less than 1.<br />
Recall that the degree of a polynomial is the highest exponent in the polynomial. Also,<br />
recall that a constant is thought of as a polynomial of degree zero. Therefore, we'll need<br />
to continue until we get a constant in this case.<br />
Here is the rest of the work for this example.<br />
5x² + 19x + 76<br />
x - 4 5x³ - x² + 0x + 6<br />
- (5x³ - 20x²)<br />
19x² + 0x + 6<br />
- (19x² - 76x)<br />
76 + 6<br />
- (76x - 304)<br />
310<br />
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MATHEMATICS UNIT - 2
What is division algorithm for polynomials?<br />
Division algorithm states that : Given a polynomial P(x) with degree at least 1 and any<br />
number R there is another polynomial Q(x), called the quotient, with degree one less<br />
than the degree of P(x) and a number R, called the remainder, such that,<br />
P (x) = (x - r) Q (x) + R<br />
Division algorithm: Dividend = Divisor x Quotient + Remainder<br />
Example Divide x³ -3x² +5x -3 by x² -2<br />
(I) p(x) = x³ - 3x² + 5x - 3<br />
q(x) = x² - 2<br />
x - 3<br />
x² - 2 x³ - 3x² + 5x - 3<br />
x³ - 2x<br />
- +<br />
- 3x² + 7x - 3<br />
- 3x² +6<br />
+ -<br />
7x - 9<br />
Quotient = x - 3<br />
Remainder = 7x - 9<br />
2 4 3 2<br />
Example To check whether x +3x+1 is a factor of 3x + 5x -7x +2x+2.<br />
3x² - 4x + 2<br />
4<br />
x² + 3x + 1 3x + 5x³ - 7x² + 2x + 2<br />
4<br />
3x + 9x³ + 3x²<br />
- - -<br />
- 4x³ - 10x² + 2x + 2<br />
- 4x³ - 12x² - 4x<br />
+ + +<br />
2x² + 6x + 2<br />
2x² + 6x + 2<br />
0<br />
MATHEMATICS UNIT - 2<br />
19
Since the remainder is 0,<br />
4<br />
Hence, x² + 3x + 1 is a factor of 3x + 5x³ - 7x² + 2x + 2<br />
Discussion: How many zeroes a cubic polynomial has? Yes, you are right. A cubic<br />
polynomial has at most 3 zeroes.<br />
You have learnt how to find rational zero of a cubic polynomial. For the problem<br />
discussed earlier we were able to found one zero and mentioned that rest of the zeroes<br />
we will be able to find after learning Division Algorithm. Now, we will use the division<br />
of polynomials process to do the same.<br />
Example: If one zero of a cubic polynomial x³ - 3x² - x+3 is 1, then find the other zeroes.<br />
In this problem, it is given that one zero is 1, this means (x-1) is a factor of given<br />
polynomial.<br />
We will divide the given polynomial by (x-1).<br />
On dividing we get x³ - 3x² - x+3 = (x-1)(x²-2x-3) +0<br />
But x² - 2x - 3 can be factorised as (x+1) (x-3)<br />
.: x³ - 3x² - x + 3 = (x-1) (x²-2x-3) + 0<br />
= (x-1) (x+1) (x-3) + 0<br />
⇒Factors of the polynomial x³ - 3x² - x + 3<br />
are (x-1) (x+1) (x-3)<br />
Note : Find all zeroes of polynomial x³ - 3x + 2 = 0<br />
You already know that one zero of this polynomial is 1.<br />
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Teachers'<br />
Support<br />
Material<br />
MATHEMATICS UNIT - 2<br />
21
2.8 Activity 1- Warm up (W1)<br />
Description: This is a starter activity to engage students in learning. Show the image<br />
given below and ask the students to read the words one by one. Tell them we will play a<br />
game using these terms.<br />
Pre Preparation:<br />
Prepare paper slips on which various terms and<br />
statements are written. Put them in a bowl and<br />
ask each student to pick up one slip.<br />
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MATHEMATICS UNIT - 2
monomial<br />
A binomial having degree 4<br />
A trinomial having degree 4<br />
A constant polynomial<br />
A cubic polynomial<br />
A quadratic polynomial<br />
A trinomial whose constant<br />
term is 1<br />
Execution: Each student will have to say one sentence about the written terms or give<br />
examples in support of statement on the slip.<br />
MATHEMATICS UNIT - 2<br />
23
2.9 Activity 2- Warm up (W2)<br />
Specific Objectives:<br />
• To explore an algebraic expression and find whether it is a polynomial or not?<br />
• To find If the given expression is a polynomial then it is a polynomial in one variable<br />
or not?<br />
• To find If the given expression is a polynomial then observe its degree and count the<br />
number of terms<br />
• To name the given polynomial according to its degree.<br />
• To name the given polynomial according to the number of terms in it.<br />
Description: This is a brainstorming warm up activity. Write any algebraic<br />
expression on the board. Students will be asked to comment on the expression. They<br />
will brainstorm on various aspects<br />
• Is it a polynomial? Why and Why not?<br />
• If yes, then what is the degree? What will you call it on the basis of degree?<br />
• How many terms are there? What will you call it on the basis of number of terms?<br />
• What are the coefficients of various terms?<br />
Pre preparation:<br />
Make a list of various algebraic polynomials.<br />
Some of them are not to be polynomials.<br />
Prepare a list of points for brainstorming.<br />
Terms: Monomial, Binomial, Trinomial, Polynomial, Degree, Quadratic polynomial,<br />
Cubic Polynomial, Coefficients<br />
24<br />
MATHEMATICS UNIT - 2
Execution :<br />
Consider the given algebraic expression<br />
4x³ + 3x² - 5x - 6<br />
Ask the students to write observations on the following statements<br />
1. The given algebraic expression is a polynomial<br />
2. It is a polynomial in one variable<br />
3. The coefficient of x is 5<br />
4. Its constant term is 6<br />
5. Its degree is 5<br />
6. It is a cubic polynomial<br />
7. It has 4 terms<br />
8. The coefficient of x² is 3<br />
9. If we remove -5x term then it will become a trinomial<br />
10. If we remove any of one term, then it will become a trinomial<br />
11. If we add one more term having degree 4 then it will become a polynomial of degree 4.<br />
MATHEMATICS UNIT - 2<br />
25
2.10 Activity 3 Pre Content (P1)<br />
Specific Objectives:<br />
• To recall the concept of value of a polynomial at a given point<br />
• To practice to find the value of a polynomial at a given point<br />
• To revise the concept of zero of a linear polynomial<br />
Description: Students have studied in class 9 to find the value of a polynomial at a given<br />
point. Also, they have learnt to calculate zeroes of a linear polynomial. For example, to<br />
calculate the zero of linear polynomial p(x) = 3x -2, put 3x-2 = 0. So, the zero of p(x) = 3x -<br />
2 will be 2/3.<br />
Prepare a worksheet for students for testing the previous knowledge based on two<br />
concepts.<br />
2 Finding the value of a polynomial at a given point<br />
3 Zeroes of a linear polynomial<br />
Execution: Ask the students to solve the worksheet. Discuss orally the important<br />
points. Let students speak the method of finding zero of a linear polynomial.<br />
Specific Objectives:<br />
Description:<br />
2.11 Activity 4 Content Worksheet (CW1)<br />
• to be able to write linear and quadratic polynomials<br />
• to be able to find the zeroes of a linear polynomial<br />
• to be able to find the zeroes of a quadratic polynomial by splitting the middle term<br />
After learning to find the zeroes of a polynomial, students will be provided with<br />
content worksheet CW1. It is a 20 minutes task in which students will use their<br />
knowledge and solve the exercise given in the worksheet.<br />
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MATHEMATICS UNIT - 2
Follow up:<br />
Revise important points learnt till now. Ask the students to make a mind map.<br />
Specific Objectives:<br />
2.12 Activity5 Content Worksheet (CW2)<br />
• To find the zeroes of a quadratic polynomial and verify the relationship between zeroes<br />
and coefficients<br />
• To write a quadratic polynomial when its zeroes are given<br />
• To write a quadratic polynomial when sum and product of its zeroes are given<br />
Description: After learning how to find the zeroes of a quadratic polynomial, students<br />
will be given a worksheet on finding a relationship between zeroes and coefficients of a<br />
quadratic polynomial. Students will use the knowledge of splitting the middle term<br />
concept and find the zeroes of a given quadratic polynomial. They will further verify<br />
the relationship between zeroes and coefficients of the polynomial.<br />
Specific Objectives:<br />
2.13 Activity 6 Content Worksheet (CW3)<br />
• To practice the skill of drawing graphs of a linear polynomial on a graph paper<br />
• To observe the graph of a polynomial and tell the number of zeroes<br />
• To tell the value of zero(s) of a polynomial from its graph<br />
Description: Teacher will ask the students to write a linear polynomial and draw its<br />
graph. Each student will make the table of values and plot the points on a graph paper.<br />
Students will be then asked to observe the points where the graph intersects the x- axis<br />
(if any).<br />
Let students verify that the abscissa of the point where the graph intersects the x- axis is<br />
the required zero of the given polynomial.<br />
MATHEMATICS UNIT - 2<br />
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2.14 Activity 7 Content Worksheet (CW4)<br />
Specific Objectives:<br />
To observe the number of zeroes of a polynomial from its graph.<br />
Description:<br />
Students will be asked to observe the graphs of polynomials. They will be asked.<br />
(i) Is the graph intersecting x-axis at any point?<br />
(ii) At, how many points, the graph in intersecting x-axis?<br />
Hence, how much zeroes, the polynomials have?<br />
Specific Objectives:<br />
Description<br />
2.15 Activity 8 Content Worksheet (CW5)<br />
To divide a polynomials of degree more than 1 by a linear polynomial.<br />
To find the quotient and the remainder.<br />
To understand the division algorithm to establish that<br />
Dividend = Divisor x Quotient + Remainder.<br />
Students will be given two polynomials p(x) and g(x) and will be asked.<br />
1. Which of these polynomials can be divided by the other?<br />
2. What will be the degree of quotient?<br />
3. What will be the degree of the remainder?<br />
Take different examples of p(x) and g(x) and find q(x), the quotient and r(x), the<br />
remainder.<br />
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MATHEMATICS UNIT - 2
2.16 Useful Resources<br />
(i)<br />
http://www.sosmath.com/algebra/factor/fac01/fac01.html<br />
(On this web page the process of long division of polynomials is explained step by step)<br />
(ii)<br />
http://www.mathsisfun.com/algebra/polynomials-division-long.html<br />
(On this web page, some videos are inserted for the explanation of long division in<br />
polynomials)<br />
Useful Videos<br />
i. Note: If the students find problem in splitting the middle term of a quadratic<br />
polynomial then they may watch Video: Splitting the middle term<br />
http://www.youtube.com/watch?v=07IenNnS3Xs<br />
ii. http://www.youtube.com/watch?v=FsotIB0Usvw<br />
iii.<br />
Dividing a quadratic polynomial by a linear polynomial<br />
http://www.youtube.com/watch?v=l6_ghhd7kwQ&feature=relmfu<br />
MATHEMATICS UNIT - 2<br />
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Students'<br />
Support<br />
Material<br />
MATHEMATICS UNIT - 2<br />
31
Student's Worksheet-1<br />
Warm up (W1)<br />
Name of student______________________________________<br />
Date__________________<br />
Consider the given algebraic expression<br />
3 2<br />
4x + 3x - 5x - 6<br />
Give your comments on the following statements:<br />
• The coefficient of x is 5<br />
_____________________________________________________________<br />
• This is a polynomial<br />
_____________________________________________________________<br />
• Its constant term is -6<br />
_____________________________________________________________<br />
• Its degree is 5<br />
_____________________________________________________________<br />
• It is a cubic polynomial.<br />
_____________________________________________________________<br />
• It has 4 terms<br />
_____________________________________________________________<br />
• The coefficient of x² is 3<br />
_____________________________________________________________<br />
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• If we remove -5x term then it will become a trinomial<br />
_____________________________________________________________<br />
• If we remove any of one term, then it will become a trinomial<br />
_____________________________________________________________<br />
• If we add one more term having degree 4 then it will become a polynomial of degree 4.<br />
_____________________________________________________________<br />
Student's Worksheet - 1A<br />
Warm up (W2)<br />
Name of student________________________________________<br />
Date__________________<br />
Understanding of terms along with their meaning<br />
MATHEMATICS UNIT - 2<br />
33
Self Assessment Rubric - 1<br />
Term<br />
Polynomial<br />
Monomial<br />
Binomial<br />
Trinomial<br />
Linear Polynomial<br />
Quadratic Polynomial<br />
Cubic Polynomial<br />
Quartic Polynomial<br />
Coefficient of terms<br />
Degree of polynomial<br />
Knows the meaning Aware of the term but<br />
do not know the<br />
meaning<br />
Do not know<br />
what it is?<br />
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MATHEMATICS UNIT - 2
Student's Worksheet-2<br />
Pre content (P1)<br />
Name of student_________________________________________<br />
Date___________________<br />
Choose the correct answer.<br />
1. The zero of the polynomial P(x) = x+5 is<br />
(i) 5 (ii) -5 (iii) 0 (iv) 1<br />
3<br />
2. The remainder when x +1 is divided by x+1 is<br />
(i) 1 (ii) 2 (iii) -1 (iv) 0<br />
3 2<br />
3. If x-1 is a factor of 4x +3x -4x+K, then value of K is<br />
(i) 3 (ii) -3 (iii) 0 (iv) -2<br />
2<br />
4. The value of the polynomial 5x-4x +3 at x= -1 is<br />
(i) 6 (ii) -1 (iii) -6 (iv) 3<br />
Fill the table given below<br />
Polynomial<br />
3<br />
P(x)= 4x -5x+2<br />
2<br />
P(t) = 5t +3t -8<br />
Value<br />
P(2)=<br />
P(1)=<br />
P(y)=7y² + 2u - 1 P(½) =<br />
4 3<br />
P(r) = 4r + 7y + 2 P(0) =<br />
P(y) = 1 - ½y³ P(-1) =<br />
P(r)= ar³ + 1 P(1) =<br />
MATHEMATICS UNIT - 2<br />
35
Self Assessment Rubric 2<br />
Student's Worksheet-3<br />
Pre Content (P1)<br />
Name of student____________________________<br />
Date__________________<br />
Rate your knowledge according to the given scale.<br />
Skill<br />
Able to find the zero of a<br />
linear polynomial<br />
Able to apply Remainder<br />
theorem<br />
Able to apply factor<br />
theorem<br />
Able to find value of a<br />
polynomial at a given point<br />
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Student's Worksheet-4<br />
Content Worksheet (CW1)<br />
Name of student_____________________________________________ Date______________<br />
1. Write two examples each of a linear polynomial and a quadratic polynomial.<br />
Type of polynomial<br />
Examples<br />
Linear<br />
Quadratic<br />
2. Find the zeroes of following linear polynomials.<br />
a) P(x) = 7x +3<br />
b) Q(t) = 3t -2<br />
3. Take any three linear polynomials. Find the zeroes. How many zeroes a linear<br />
polynomial has?<br />
___________________________________________________________________________<br />
___________________________________________________________________________<br />
___________________________________________________________________________<br />
___________________________________________________________________________<br />
___________________________________________________________________________<br />
___________________________________________________________________________<br />
MATHEMATICS UNIT - 2<br />
37
4. Factorise the following quadratic polynomials using the splitting the middle term. Find<br />
the zeroes.<br />
2<br />
a) 5x -6x + 1<br />
2<br />
b) t -2x-8<br />
2<br />
c) 4m -4m+1<br />
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MATHEMATICS UNIT - 2
Self Assessment Rubric 3<br />
Student's Worksheet-5<br />
Content Worksheet (CW1)<br />
Name of student_________________________________________<br />
Date__________________<br />
Rate your knowledge according to the given scale.<br />
Skill<br />
Able to write a linear/<br />
quadratic/cubic polynomial<br />
Able to find zeroes of a<br />
linear polynomial<br />
Able to find zeroes of a<br />
quadratic polynomial<br />
MATHEMATICS UNIT - 2<br />
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Student's Worksheet-6<br />
Content Worksheet (CW2)<br />
Name of student_____________________________________________ Date______________<br />
Assignment:<br />
Q1<br />
Find the zeroes of the following quadratic polynomials and verify the relationship<br />
between zeroes and coefficients.<br />
(a) x² + 8x + 12<br />
(b) x² + 3x - 4<br />
(c) x² - 7x + 10<br />
(d) y² - 4<br />
Q2<br />
Q3<br />
Q4<br />
Find a quadratic polynomial each with the given numbers as the sum and product of its<br />
zeroes respectively:<br />
3 3<br />
(a) 3 and 4 (b) -2 and (c) - and 0 (d) -2 and 3<br />
2 2<br />
Find a quadratic polynomial with -1 as zero.<br />
Find a cubic polynomial with zeroes as 2, -2½.<br />
Q5 Find a cubic polynomial with zeroes 1, 1, 2.<br />
Q6 Find a cubic polynomial with zeroes -1, -1, -1.<br />
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Self Assessment Rubric 4<br />
Student's Worksheet-7<br />
Content Worksheet (CW2)<br />
Name of student_________________________________________<br />
Date__________________<br />
Rate your knowledge according to the given scale.<br />
Skill<br />
Able to verify the relation<br />
b e t w e e n z e r o e s a n d<br />
coefficient<br />
Able to write a quadratic<br />
polynomial when its zeroes<br />
are given<br />
Able to write a quadratic<br />
polynomial when sum and<br />
product of its zeroes is<br />
given<br />
MATHEMATICS UNIT - 2<br />
41
Student's Worksheet-8<br />
Content Worksheet (CW3)<br />
Name of student_________________________________________<br />
Date__________________<br />
1. Draw the graph of y = 2x + 5.<br />
X<br />
Y<br />
Find the points where the straight line cuts the x- axis and the y- axis.<br />
The straight line cuts the x- axis at ……………………..<br />
The straight line cuts the y- axis at …………………….<br />
Now, to get zero, 2x + 5 = 0<br />
⇒x = -5/2<br />
Observe that the graph of y = 2x + 5 intersects the x- axis at the point ( -5/2 , 0).<br />
Note: The zero of the polynomial 2x + 5 is the x-coordinate of the point i.e. - 5/2 where the<br />
graph of y = 2x + 5 intersects the x-axis.<br />
2. Draw the graph of following linear polynomials. Find the zero from the graph. How<br />
many zeroes a linear polynomial has? Verify you answer.<br />
a) 5x-3<br />
b) 2x+6<br />
c) 6x-2<br />
d) 2x-4<br />
42<br />
MATHEMATICS UNIT - 2
3. The graph of y = p(x) are drawn below. Mark the number of zeros in each case:<br />
a) b)<br />
c) d)<br />
e) f)<br />
MATHEMATICS UNIT - 2<br />
43
Self Assessment Rubric 5<br />
Student's Worksheet-9<br />
Content Worksheet (CW3)<br />
Name of student_________________________________________<br />
Date__________________<br />
Rate your knowledge according to the given scale.<br />
Skill<br />
Able to draw the graph of a<br />
linear polynomial<br />
Able to find zeroes of a<br />
linear polynomial from its<br />
graph<br />
Able to find zeroes of a<br />
polynomial from its graph<br />
44<br />
MATHEMATICS UNIT - 2
Student's Worksheet-10<br />
Content Worksheet (CW4)<br />
Name of student_________________________________________<br />
Date__________________<br />
• A polynomial of degree n has at most n zeroes.<br />
• Geometrically the zeroes of a polynomial are x coordinates of points where the graph of<br />
polynomial cuts/touches the x-axis.<br />
The zeroes of a polynomial p(x) are precisely the x-coordinates of the points, where the<br />
graph of y = p(x) intersects the x -axis.<br />
Observe the given graphs and fill the respective rows.<br />
S. No. Graph of y = f(x)<br />
1. Graph of a<br />
linear<br />
polynomial<br />
Number of Zeroes<br />
Zeroes<br />
2. Graph of a<br />
quadratic<br />
polynomial<br />
MATHEMATICS UNIT - 2<br />
45
S. No. Graph of y = f(x)<br />
3. Graph of a<br />
quadratic<br />
polynomials<br />
Number of Zeroes<br />
Zeroes<br />
4. Graph of a<br />
quadratic<br />
polynomial<br />
46<br />
MATHEMATICS UNIT - 2
Self Assessment Rubric 6<br />
Student's Worksheet-11<br />
Content Worksheet (CW4)<br />
Name of student_________________________________________<br />
Date__________________<br />
Rate your knowledge according to the given scale.<br />
Skill<br />
Able to find number of<br />
zeroes of a polynomial<br />
from its graph<br />
Able to find zeroes of a<br />
polynomial from its graph<br />
MATHEMATICS UNIT - 2<br />
47
Student's Worksheet-12<br />
Content Worksheet (CW5)<br />
Name of student_________________________________________<br />
Date__________________<br />
Exercise:<br />
1. Apply the division algorithm to find the quotient and the remainder on dividing p(x) by<br />
q(x)<br />
3 2<br />
I. p(x)= x +15x +48x, q(x)= x+8<br />
3 2<br />
ii. p(x) = 14x -5x +9x-1, q(x) = 2x-1<br />
2. Check whether the first polynomial is a factor of the second polynomial by dividing the<br />
second polynomial by the first polynomial:<br />
2<br />
a) (x-1), 5x -3x+2<br />
2<br />
b) (x+1), 2x +5x+3<br />
3 2<br />
3. On dividing x -3x +5x -3 by a polynomial g(x), the quotient is (x-3) and the remainder is<br />
(7x-9). Find g(x). Write the formula used.<br />
3 2<br />
4. Find the value of a and b so that 1, -2 are the zeroes of the polynomial x + 10x + ax + b.<br />
5. Divide the polynomial p(x) by q(x) in each of the following cases and find the quotient<br />
and remainder:<br />
3<br />
a) p(x) = 7x - 5x + 8 q(x) = x - ½<br />
b) p(x) = 6x² - 5x² + 4x + 3 q(x) = 4x² + 1<br />
c) p(x) = 16x³ - 4x² + 2x + 7 q(x) = 2x - 1<br />
48<br />
MATHEMATICS UNIT - 2
Self Assessment Rubric 7<br />
Student's Worksheet-13<br />
Content Worksheet (CW5)<br />
Name of student_________________________________________<br />
Date__________________<br />
Rate your knowledge according to the given scale.<br />
Skill<br />
Able to divide a quadratic polynomial by<br />
a linear polynomial<br />
Able to divide a cubic polynomial by a<br />
linear polynomial<br />
Able to divide a cubic polynomial by a<br />
quadratic polynomial<br />
Able to verify division algorithm for<br />
polynomials<br />
Able to find zeroes of a polynomial using<br />
division algorithm<br />
MATHEMATICS UNIT - 2<br />
49
Student's Worksheet-14<br />
Post Content Worksheet (PCW1)<br />
1. Fill in the blanks<br />
i. Polynomials of degrees 1, 2 and 3 are called………….. , …………….. And cubic<br />
polynomials respectively.<br />
2<br />
ii. A…………… polynomial in x with real coefficients is of the form ax + bx + c, where<br />
a, b,c are real numbers with a?0.<br />
iii. The zeroes of a polynomial p(x) are precisely the …………………… of the points,<br />
where the graph of y = p(x) intersects the x -axis.<br />
iv. A quadratic polynomial can have at most ………….. zeroes and a cubic polynomial<br />
can have at most …………… zeroes.<br />
v. If and βare the zeroes of the quadratic polynomial ax² + bx + c, then<br />
a. α+ β= …………… and αβ= …………………<br />
vi. The division algorithm states that given any polynomial p(x) and any non-zero<br />
polynomial g(x), there are polynomials q(x) and r(x) such that<br />
p(x) = g(x) q(x) + r(x),where r(x) = 0 or degree r(x) ……………. degree g(x).<br />
2. Find the quadratic polynomial, the sum and product of whose zeroes are<br />
1) ½, -2<br />
2) -3, -7<br />
3) 5+√3 & 5-√2<br />
3. Find the zeroes of the quadratic polynomial p(x) =t ² - 15<br />
4. How many maximum zeroes can a polynomial of degree two has?<br />
5. What is the zero of the polynomial ax + b=0, a≠0?<br />
6. Find the sum & the product of the zeroes of the polynomial 6x²-x-2.<br />
50<br />
MATHEMATICS UNIT - 2
7. Give examples of polynomials f(x), g(x), q(x) & r(x) which satisfy the division algorithm<br />
1) deg r(x)=0<br />
2) deg f(x)=deg q(x)=2<br />
8. Find the quadratic polynomial whose one zero is 5 & product of zeroes is 30.<br />
9. The linear polynomial ax + b, a ? 0, has exactly one zero, namely, the__________ of the<br />
point where the graph of y = ax + b intersects the x-axis.<br />
10. Divide the polynomial p(x) by the polynomial g(x) and find the quotient and remainder<br />
in each of the following:<br />
3 2 2<br />
(i ) p(x)=x -3x +5x-3,g(x)=x -2<br />
3 2 2<br />
(ii) p(x) = x - 3x + 4x + 5, g(x) = x + 1 - x<br />
Student's Worksheet-15<br />
Post Content Worksheet (PCW2)<br />
1. Express the polynomial given in column I in the form of and match with the<br />
coefficients of their terms in Column II<br />
COLUMN I<br />
COLUMN II<br />
x² + 6x a = 1 b = 0 c = 6<br />
x² + 6 a = 0 b = 1 c = 6<br />
x+ 6 a = 1 b = 6 c = 0<br />
2. Match the polynomials in column I with their zeros in column II<br />
COLUMN I<br />
COLUMN II<br />
x² - 5x - 6 α= -6 β= 1<br />
x² + 5x - 6 α= -6 β= 1<br />
x² - 7x + 6 α= -6 β= 1<br />
x² + 7x + 6 α= -6 β= 1<br />
MATHEMATICS UNIT - 2<br />
51
3. Fill in the appropriate boxes:<br />
Dividend Divisor Quotient Remainder<br />
x² + 3x + 4 x + 1 2<br />
x² + 7x + 7 x + 5 1<br />
x² - 5x + 6 x - 1 -2<br />
x² - 3x - 12 x - 5 x + 2<br />
4. Fill in the blanks:-<br />
i) The zeroes of the polynomial ________________ are -3 and -4.<br />
ii) The remainder is ________________ when x³ + 5x² + 3x - 2 is divided by x + 1 .<br />
iii)<br />
If the zeroes of the polynomial are 5 and 6 then the co-efficient of is _________.<br />
iv)<br />
If the zeroes of the polynomial are opposite in sign then the co-efficient of x is<br />
______.<br />
v) The sum and product of zeroes of the polynomial ______________ are -2 and<br />
vi)<br />
The polynomial x² + 10x + 25 has______________ roots.<br />
-3<br />
2<br />
vii)<br />
If a polynomial of degree five is divided by a quadratic polynomial then the<br />
degree of the quotient polynomial is _______________.<br />
viii) The quotient polynomial is ______________ if the two zeroes of the polynomial<br />
x³ + 5x² - 4x + 5 are 2 and -2.<br />
52<br />
MATHEMATICS UNIT - 2
Assessment guidance plan for teachers<br />
With each task in student support material a self -assessment rubric is attached for students.<br />
Discuss with the students how each rubric can help them to keep in tune their own progress.<br />
These rubrics are meant to develop the learner as the self motivated learner.<br />
To assess the students' progress by teacher two types of rubrics are suggested below, one is for<br />
formative assessment and one is for summative assessment.<br />
Suggestive Rubric for Formative Assessment (exemplary)<br />
Parameter<br />
Mastered<br />
Developing<br />
Needs motivation<br />
Needs personal<br />
attention<br />
Factorisatio<br />
n of<br />
polynomial<br />
Able to factorise<br />
quadratic<br />
polynomial by<br />
splitting of middle<br />
term<br />
Able to factorise<br />
quadratic<br />
polynomial using<br />
formula<br />
Able to find atleast<br />
one factor using<br />
leading coefficient<br />
and constant term<br />
Able to use division<br />
of polynomials to<br />
find other factor<br />
Able to find out the<br />
factors of cubic<br />
polynomial by<br />
grouping them<br />
Able to find out<br />
atleast one factor by<br />
use of leading<br />
coefficients and<br />
constant term<br />
Able to find other<br />
factors using<br />
division of<br />
polynomials and<br />
repeating the same<br />
procedure to get all<br />
factors<br />
From above rubric it is very clear that<br />
Able to factorise<br />
quadratic<br />
polynomial by<br />
splitting of middle<br />
term<br />
Able to factorise<br />
quadratic<br />
polynomial using<br />
formula<br />
Able to find atleast<br />
one factor using<br />
leading coefficient<br />
and constant term<br />
Able to use<br />
division of<br />
polynomials to find<br />
other factor<br />
Able to find out the<br />
factors of cubic<br />
polynomial by<br />
grouping them<br />
Able to find out<br />
atleast one factor<br />
by use of leading<br />
coefficients and<br />
constant term<br />
Able to find other<br />
factors using<br />
division of<br />
polynomials but<br />
not able to repeat<br />
the same procedure<br />
to get all factors<br />
Able to factorise<br />
quadratic<br />
polynomial by<br />
splitting of middle<br />
term<br />
Not able to<br />
factorise quadratic<br />
polynomial using<br />
formula<br />
Able to find atleast<br />
one factor using<br />
leading coefficient<br />
and constant term<br />
Not able to use<br />
division of<br />
polynomials to<br />
find other factor<br />
Not able to find<br />
out the factors of<br />
cubic polynomial<br />
by grouping them<br />
Able to find out<br />
atleast one factor<br />
by use of leading<br />
coefficients and<br />
constant term<br />
Not able to find<br />
other factors using<br />
division of<br />
polynomials and<br />
repeating the same<br />
procedure to get<br />
all factors<br />
Not able to factorise<br />
quadratic<br />
polynomial by<br />
splitting of middle<br />
term<br />
Not able to factorise<br />
quadratic<br />
polynomial using<br />
formula<br />
Not able to find<br />
atleast one factor<br />
using leading<br />
coefficient and<br />
constant term<br />
Not able to use<br />
division of<br />
polynomials to find<br />
other factor<br />
Not able to find out<br />
the factors of cubic<br />
polynomial by<br />
grouping them<br />
Not able to find out<br />
atleast one factor by<br />
use of leading<br />
coefficients and<br />
constant term<br />
Not able to find<br />
other factors using<br />
division of<br />
polynomials and<br />
repeating the same<br />
procedure to get all<br />
factors<br />
MATHEMATICS UNIT - 2<br />
53
•<br />
•<br />
•<br />
•<br />
Learner requiring personal attention is poor in concepts and requires the<br />
training of basic concepts before moving further.<br />
Learner requiring motivation is able to do a lot but stuck up with division of<br />
polynomials. He can be trained by peer trainers or by doing remedial<br />
worksheets.<br />
Learner who is developing is able to almost all type of problems but needs more<br />
practice to solve cubic polynomials and to understand how the procedure can be<br />
repeated.<br />
Learner who has mastered the skill of factorisation of polynomials can be given<br />
higher order polynomials for factorisation.<br />
Teachers' Rubric for Summative Assessment of the <strong>Unit</strong><br />
Parameter<br />
Factorisation of<br />
polynomial<br />
algebraically<br />
Finding zeroes<br />
of polynomial<br />
Division<br />
algorithm<br />
5<br />
• Able to factorise<br />
quadratic polynomial<br />
• Able to factorise cubic<br />
polynomial<br />
• Able to factorise<br />
biquadratic polynomial<br />
• Able to find zeroes of<br />
polynomial by<br />
factorising it.<br />
• Able to read zeroes<br />
from graph of<br />
polynomial<br />
• Able to find zeroes of<br />
polynomial using the<br />
relation between<br />
coefficients of<br />
polynomial and its<br />
zeroes.<br />
• Able to divide linear<br />
polynomial by a linear<br />
polynomial.<br />
• Able to divide<br />
quadratic polynomial<br />
by a linear polynomial.<br />
• Able to divide cubic<br />
polynomial by a linear<br />
polynomial.<br />
• Able to divide cubic<br />
polynomial by a<br />
quadratic polynomial.<br />
1<br />
• Not able to factorise<br />
quadratic polynomial<br />
• Not able to factorise<br />
cubic polynomial<br />
• Not able to factorise<br />
biquadratic polynomial<br />
• Not able to find zeroes of<br />
polynomial by<br />
factorising it.<br />
• Not able to read zeroes<br />
from graph of<br />
polynomial<br />
• Not able to find zeroes of<br />
polynomial using the<br />
relation between<br />
coefficients of<br />
polynomial and its<br />
zeroes.<br />
• Not able to divide linear<br />
polynomial by a linear<br />
polynomial.<br />
• Not able to divide<br />
quadratic polynomial by<br />
a linear polynomial.<br />
• Not able to divide cubic<br />
polynomial by a linear<br />
polynomial.<br />
• Not able to divide<br />
cubic polynomial by a<br />
quadratic polynomial.<br />
54<br />
MATHEMATICS UNIT - 2
CENTRAL BOARD OF SECONDARY EDUCATION<br />
Shiksha Kendra, 2, Community Centre, Preet Vihar,<br />
Delhi-110 092 India