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NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

Last Updated : 19 Mar, 2024
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NCERT Solutions for Class 10 Maths Chapter 2 Polynomials- This article is an important resource created by the GFG team of experts to help students solve problems in the NCERT Textbook in an easy manner. It contains free NCERT Solutions for Class 10 Maths Chapter 2 Polynomials, as per the latest CBSE syllabus 2023-2024 and guidelines.

Class 10 Maths NCERT Solutions Chapter 2 Polynomials Exercises

Chapter 2 Polynomials of NCERT Class 10 Maths deal majorly in topics such as fundamental aspects of polynomials. Students learn about the basic definitions, terms, coefficients, and degrees of polynomials. They study several polynomial varieties and comprehend polynomial operations including addition, subtraction, multiplication, and division. Factorization methods for quadratic polynomials are introduced, along with concepts like the factor theorem and remainder theorem. The chapter also delves into finding zeros of polynomials.

All the solutions to NCERT Class 10 Maths Chapter 2 Polynomials exercises have been covered in NCERT Solutions for Class 10 Maths.

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials: Exercise 2.1

Question 1. The graphs of y = p(x) are given in Fig. below, for some polynomials p(x). Find the number of zeroes of p(x), in each case.

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

Solution:

So, we have equation y = p(x). When p(x) = 0, y = 0. 

That means we only need to find the number of times we get y = 0 in the graph.

In other words, the number of times the graph intersects the x-axis is the answer.

(i) 0. Because the graph doesn’t intersect the x-axis.

(ii) 1. Because the graph intersects the x-axis only at one point.

(iii) 3. Because the graph intersects the x-axis at three points.

(iv) 2. Because the graph intersects the x-axis at two points.

(v) 4. Because the graph intersects the x-axis at four points.

(vi) 3. Because the graph intersects the x-axis at three points.

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials: Exercise 2.2

Question 1. Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients.

(i) x2 – 2x – 8

x2 – 2x – 8 = x2 – 4x + 2x – 8 

= x (x – 4) + 2(x – 4) 

= (x – 4) (x + 2)

Therefore, zeroes of equation x2 – 2x – 8 are (4, -2)

Sum of zeroes is equal to [4 – 2]= 2 = -(-2)/1 

i.e. = -(Coefficient of x) / (Coefficient of x2)

Product of zeroes is equal to 4 × (-2) = -8 =-(8)/1  

i.e.= (Constant term) / (Coefficient of x2)

(ii) 4s2 – 4s + 1

4s2 – 4s + 1 = 4s2 – 2s – 2s +1 

= 2s(2s – 1) – 1(2s – 1) 

= (2s – 1) (2s – 1)

Therefore, zeroes of  equation 4s2 – 4s +1 are (1/2, 1/2)

Sum of zeroes is equal to [(1/2) + (1/2)] = 1 = -4/4 

i.e.= -(Coefficient of s) / (Coefficient of s2)

Product of zeros is equal to [(1/2) × (1/2)] = 1/4 

i.e.= (Constant term) / (Coefficient of s2 )

(iii) 6x2 – 3 – 7x

6x2 – 3 – 7x = 6x2 – 7x – 3 

= 6x2 – 9x + 2x – 3 

= 3x(2x – 3) + 1(2x – 3) 

= (3x + 1) (2x – 3)

Therefore, zeroes of equation 6x2 – 3 – 7x are (-1/3, 3/2)

Sum of zeroes is equal to -(1/3) + (3/2) = (7/6) 

i.e.= -(Coefficient of x) / (Coefficient of x2)

Product of zeroes is equal to -(1/3) × (3/2) = -(3/6) 

i.e.= (Constant term) / (Coefficient of x2 )

(iv) 4u2 + 8u

4u2 + 8u = 4u(u + 2)

Therefore, zeroes of equation 4u2 + 8u are (0, -2).

Sum of zeroes is equal to [0 + (-2)] = -2 = -(8/4)

i.e. = -(Coefficient of u) / (Coefficient of u2)

Product of zeroes is equal to 0 × -2 = 0 = 0/4 

i.e. = (Constant term) / (Coefficient of u2 )

(v) t2 – 15

 t2 – 15

⇒ t2 = 15 or t = ±√15

Therefore, zeroes of equation t2 – 15 are (√15, -√15)

Sum of zeroes is equal to [√15 + (-√15)] = 0 = -(0/1) 

i.e.= -(Coefficient of t) / (Coefficient of t2)

Product of zeroes is equal to √15 × (-√15) = -15 = -15/1 

i.e. = (Constant term) / (Coefficient of t2 )

(vi) 3x2 – x – 4

3x2 – x – 4 = 3x2 – 4x + 3x – 4

= x(3x – 4) + 1(3x – 4) 

= (3x – 4) (x + 1)

Therefore, zeroes of equation 3x2 – x – 4 are (4/3, -1)

Sum of zeroes is equal to (4/3) + (-1) = (1/3) = -(-1/3) 

i.e. = -(Coefficient of x) / (Coefficient of x2)

Product of zeroes is equal to (4/3) × (-1) = (-4/3) 

i.e. = (Constant term) / (Coefficient of x2)

Question 2. Find a quadratic polynomial each with the given numbers as the sum and product of its zeroes respectively.

(i) 1/4, -1

Let two zeroes be α, β

∴ Sum of zeroes = α + β

∴ Product of zeroes = αβ

Given, Sum of zeroes = α + β = 1/4

Product of zeroes = α β = -1

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – (1/4)x +(-1) = 0

4x2 – x – 4 = 0

∴ 4x2 – x – 4 is the quadratic polynomial.

(ii) √2, 1/3

Let two zeroes be α, β

∴ Sum of zeroes = α + β

∴ Product of zeroes = αβ

Given Sum of zeroes = α + β =√2

Product of zeroes = αβ = 1/3

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:

x2 – (α + β)x + αβ = 0

x2 – (√2)x + (1/3) = 0

3x2 – 3√2x + 1 = 0

∴ 3x2 – 3√2x + 1 is the quadratic polynomial.

(iii) 0, √5

Let two zeroes be α, β

∴ Sum of zeroes = α + β

∴ Product of zeroes = αβ

Given, Sum of zeroes = α + β = 0

Product of zeroes = αβ = √5

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – (0)x + √5 = 0

∴ x2 + √5 is the quadratic polynomial.

(iv) 1, 1

Let two zeroes be α, β

∴ Sum of zeroes = α + β

∴ Product of zeroes = αβ

Given, Sum of zeroes = α + β = 1

Product of zeroes = αβ = 1

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – x + 1 = 0

∴ x2 – x + 1 is the quadratic polynomial.

(v) -1/4, 1/4

Let two zeroes be α, β

∴ Sum of zeroes = α + β

∴ Product of zeroes = αβ

Given, Sum of zeroes = α + β = -1/4

Product of zeroes = α β = 1/4

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – (-1/4)x + (1/4) = 0

4x2 + x + 1 = 0

∴ 4x2 + x + 1 is the quadratic polynomial.

(vi) 4, 1

Let two zeroes be α, β

∴ Sum of zeroes = α + β

∴ Product of zeroes = αβ

Given, Sum of zeroes = α + β = 4

Product of zeroes = αβ = 1

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:

x2 – (α + β)x + αβ = 0

x2 – 4x + 1 = 0

∴ x2 – 4x + 1 is the quadratic polynomial.

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials: Exercise 2.3

Question 1. Divide the polynomial p(x) by the polynomial g(x) and find the quotient and remainder in each of the following:

(i) p(x) = x3 – 3x2 + 5x – 3, g(x) = x2 – 2

(ii) p(x) = x4 – 3x2 + 4x + 5, g(x) = x2 + 1 – x

(iii) p(x) = x4– 5x + 6, g(x) = 2 – x2

Solution:

i) p(x) = x3 – 3x2 + 5x – 3, g(x) = x2 – 2

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

R = 7x-9

Q = x-3

ii) p(x) = x4 – 3x2 + 4x + 5, g(x) = x2 + 1 – x

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

R = 8

Q = x2+x-3

iii) p(x) = x4– 5x + 6, g(x) = 2 – x2

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

Q = -x2-2

R = -5x+10

Question 2. Check whether the first polynomial is a factor of the second polynomial by dividing the second polynomial by the first polynomial.

(i) t2 – 3, 2t4 + 3t3 – 2t2– 9t – 12

(ii) x2 + 3x + 1, 3x4 + 5x3 – 7x2 + 2x + 2

(iii) x3 – 3x + 1, x5 – 4x3 + x2 + 3x + 1

Solution:

i) t2 – 3, 2t4 + 3t3 – 2t2– 9t – 12

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

Q = 2t3+3t+4

R = 0

Yes 1st polynomial is factor of 2nd polynomial. 

ii) x2 + 3x + 1, 3x4 + 5x3 – 7x2 + 2x + 2

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

R = 0

Q = 3x2-4x+2

iii) x3 – 3x + 1, x5 – 4x3 + x2 + 3x + 1

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

R = x2-1

Q = 2

Question 3. Obtain all other zeroes of 3x4 + 6x3 – 2x2 – 10x – 5, if two of its zeroes are and √(5/3) and -√(5/3).

Solution:

[Tex](x- \sqrt{\frac{5}{3}}) (x + \sqrt{\frac{5}{3}}) = x^{2}-(\sqrt{\frac{5}{3}})^{2} = x^{2}-\frac{5}{3} [/Tex]

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

R = 0

Q = 3x2+6x+3

∴ we are factorizing

3x2+6x+3

x2+2x+1

(x+1)2

(x+1)  (x+1) = 0

∴ x = -1 and x = -1

[Tex]\sqrt{\frac{5}{3}}, – \sqrt{\frac{5}{3}}, -1, -1 [/Tex]

Question 4. On dividing x3 – 3x2 + x + 2 by a polynomial g(x), the quotient and remainder were x – 2 and -2x + 4 respectively. Find g(x).

Solution:

Dividend = Divisor * Quotient + Remainder

x3-3x2+3x-2/x-2

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

R = 0

Q = x2 -x +1

Answer: g(x)=x2-x+1

Question 5. Give examples of polynomials p(x), g(x), q(x) and r(x), which satisfy the division algorithm and:

(i) deg p(x) = deg q(x)

(ii) deg q(x) = deg r(x)

(iii) deg r(x) = 0

Solution:

i) deg p(x) = deg q(x)

p(x)=2x2-2x+14, g(x)=2

p(x)/g(x)=2x2-2x+14/2=(x2-x+7)

=x2-x+7=q(x)

=q(x)=x2-x+7

r(x)=0

ii) deg q(x)=deg r(x)

p(x)=4x2+4x+4, g(x)=x2+x+1

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

q(x) = 4

r(x) = 0

∴Here deg q(x)=deg r(x)

iii) deg r(x)=0

p(x)=x3+2x2-x+2 ,g(x)=x2-1

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

q(x) = x+2

r(x) = 4

deg of r(x) = 0 

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials: Exercise 2.4

Question 1. Verify that the numbers given alongside of the cubic polynomials below are their zeroes. Also, verify the relationship between the zeroes and the coefficients in each case:

(i) 2x3 + x2 – 5x + 2; 1/2, 1, -2

Solution:

p(x) = 2x3+x2-5x+2

p(1/2) = 2(1/2)3+(1/2)2-5(1/2)+2 

           = (1/4)+(1/4)-(5/2)+2 

           = 0

p(1) = 2(1)3+(1)2-5(1)+2 = 0

p(-2) = 2(-2)3+(-2)2-5(-2)+2 = 0

Therefore, 1/2, 1, -2 are the zeroes of 2x3+x2-5x+2.

Now, comparing the given polynomial with general expression

ax3+bx2+cx+d = 2x3+x2-5x+2

a=2, b=1, c= -5 and d = 2

α, β, γ are the zeroes of the cubic polynomial ax3+bx2+cx+d

α +β+γ = –b/a

αβ+βγ+γα = c/a

α βγ = – d/a.

α+β+γ = ½+1+(-2) 

            = -1/2 = –b/a

αβ+βγ+γα = (1/2×1)+(1 ×-2)+(-2×1/2) 

                  = -5/2 = c/a

α β γ = ½×1×(-2) 

         = -2/2 = -d/a

Hence, the relationship between the zeroes and the coefficients are satisfied.

(ii) x3 – 4x2 + 5x – 2 ;2, 1, 1

Solution:

p(x) = x3-4x2+5x-2

Zeroes are 2,1,1.

p(2)= 23-4(2)2+5(2)-2 

      = 0

p(1) = 13-(4)(12 )+(5)(1)-2 = 0

Therefore, proved, 2, 1, 1 are the zeroes of x3-4x2+5x-2

On comparing the given polynomial with general expression

ax3+bx2+cx+d = x3-4x2+5x-2

a = 1, b = -4, c = 5 and d = -2

Therefore,

α + β + γ = –b/a

                = 2+1+1 

                = 4 

         –b/a = -(-4)/1

αβ + βγ + γα = c/a

                      = 2×1+1×1+1×2 

                      = 5 

                c/a = 5/1 

α β γ = – d/a.

          = 2×1×1 

          = 2 

 -d/a = -(-2)/1

Hence, the relationship between the zeroes and the coefficients is satisfied.

Question 2. Find a cubic polynomial with the sum, sum of the product of its zeroes taken two at a time, and the product of its zeroes as 2, –7, –14 respectively.

Solution:

Let us consider the cubic polynomial as ax3+bx2+cx+d and zeroes of the polynomials be α, β, γ.

α+β+γ = -b/a = 2/1

αβ +βγ+γα = c/a = -7/1

α βγ = -d/a = -14/1

On comparing

a = 1, b = -2, c = -7, d = 14

Therefore, the cubic polynomial is x3-2x2-7x+14

Question 3. If the zeroes of the polynomial x3 – 3x2 + x + 1 are a – b, a, a + b, find a and b.

Solution:

p(x) = x3-3x2+x+1

Zeroes are given as a – b, a, a + b

px3+qx2+rx+s = x3-3x2+x+1

On comparing

p = 1, q = -3, r = 1 and s = 1

Sum of zeroes = a – b + a + a + b

-q/p = 3a

Putting the values q and p.

-(-3)/1 = 3a

a=1

Therefore, zeroes are 1-b, 1, 1+b.

Product of zeroes = 1(1-b)(1+b)

-s/p = 1-b2

-1/1 = 1-b2

b2 = 1+1 = 2

b = √2

Therefore,1-√2, 1,1+√2 are the zeroes of x3-3x2+x+1.

Question 4. If two zeroes of the polynomial x4-6x3-26x2+138x-35 are 2 ±√3, find other zeroes.

Solution:

Degree of polynomial is 4

Therefore, it has four roots

f(x) = x4-6x3-26x2+138x-35

As 2 +√3 and 2-√3 are zeroes of given polynomial f(x).

Therefore, [x−(2+√3)] [x−(2-√3)] = 0

(x−2−√3)(x−2+√3) = 0

Therefore, x2-4x+1 is a factor of polynomial f(x).

Let it be g(x) = x2-4x+1

By dividing f(x) by g(x) we get another factor of f(x)

NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

x4-6x3-26x2+138x-35 = (x2-4x+1)(x2 –2x−35)

On factorizing (x2–2x−35) by splitting the middle term

x2–(7−5)x −35 = x2– 7x+5x-35

                         =x(x −7)+5(x−7)

(x+5)(x−7) = 0

x= −5 and x = 7.

Therefore, all four zeroes of given polynomial equation are: 2+√3, 2-√3, −5 and 7.

Key Features of NCERT Solutions for Class 10 Maths Chapter 2 Polynomials

  • These NCERT solutions are developed by the GfG team, with a focus on students’ benefit.
  • These solutions are entirely accurate and can be used by students to prepare for their board exams. 
  • Each solution is presented in a step-by-step format with comprehensive explanations of the intermediate steps.

Also Check:

    NCERT Solutions for Class 10 Maths Chapter 2 Polynomials – FAQs

    Q1. Why is it important to learn Chapter-2 polynomials of NCERT Class 10 Maths ?

    Polynomials are widely employed in many areas of mathematics and other disciplines. Understanding polynomials forms a strong basis for advanced algebra, calculus, and other mathematical concepts that students will come upon in their academic careers.

    Q2. What topics are covered in NCERT Solutions for Class 10 Maths Chapter 2 polynomials?

    NCERT Solutions for Class 10 Maths Chapter 2 Polynomials covers elementary concepts of polynomials, including their definition, words, coefficients, and degrees. They study several polynomial varieties and comprehend polynomial operations including addition, subtraction, multiplication, and division. Theorems like the factor theorem and the remainder theorem are introduced along with strategies for factoring quadratic polynomials. The chapter also explores polynomial zero discovery.

    Q3. How can NCERT Solutions for Class 10 Maths Chapter 2 Polynomials help me?

    NCERT Solutions for Class 10 Maths Chapter 2 Polynomials can help you solve the NCERT exercise without any limitations. If you are stuck on a problem you can find its solution in these solutions and free yourself from the frustration of being stuck on some question.

    Q4. How many exercises are there in NCERT Class 10 Maths Chapter 2 Polynomials?

    There are 4 exercises in the Class 10 Maths Chapter 2 Polynomials which covers all the important topics and sub-topics.

    Q5. Where can I find NCERT Solutions for Class 10 Chapter 2 Polynomials?

    You can find these NCERT Solutions for Class 10 Chapter 2 Polynomials in this article created by our team of experts at GeeksforGeeks.



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