# NCERT Solutions for Class 12 Maths

Download NCERT solutions for Class 12 Maths PDF format for all chapters with NCERT Solutions Apps English and Hindi Medium for UP Board (Intermediate NCERT), MP Board, Gujrat Board (2019 onward) as well as CBSE Board updated form. Download CBSE Date Sheet for 2019-2020 Examination starting from February 15, 2020. NCERT books and answers are also available to download. Share Your Knowledge and discuss your doubts in Discussion Forum.

 Class: 12 Subject: Maths – गणित Contents: NCERT Solutions

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## NCERT Solutions for Class 12 Maths

Mathematics 12 by R D Sharma is a very good book for the concepts and practice material including a lots of solved questions with proper explanation. If you have done a chapter, the Together With Maths is very good to get proper practice. Just like R D Sharma, All in One for Mathematics is also very good book with ample practice questions. CBSE Mathematics ( 15 Sample Question Papers ) is very useful after going through whole syllabus. Buy books according to your need. Download NCERT Solutions class 12 Maths PDF. Take admission in NIOS to pass class 12 in easier way.

### Main points to be recovered

#### Relations and Functions

1. Relations and Functions – summary: Types of relations: reflexive, symmetric, transitive and equivalence relations. One to one and onto functions, composite functions, inverse of a function. Binary operations.

#### Inverse Trigonometric Functions

2 Inverse Trigonometric Functions – summary: Definition, range, domain, principal value branch. Graphs of inverse trigonometric functions. Elementary properties of inverse trigonometric functions.

#### Matrices

Matrices – summary: Concept, notation, order, equality, types of matrices, zero and identity matrix, transpose of a matrix, symmetric and skew symmetric matrices. Operation on matrices: Addition and multiplication and multiplication with a scalar. Simple properties of addition, multiplication and scalar multiplication. Noncommutativity of multiplication of matrices and existence of non-zero matrices whose product is the zero matrix (restrict to square matrices of order 2).Concept of elementary row and column operations. Invertible matrices and proof of the uniqueness of inverse, if it exists; (Here all matrices will have real entries).

#### Determinants

Determinants – summary: Determinant of a square matrix (up to 3 x 3 matrices), properties of determinants, minors, co-factors and applications of determinants in finding the area of a triangle. Adjoint and inverse of a square matrix. Consistency, inconsistency and number of solutions of system of linear equations by examples, solving system of linear equations in two or three variables (having unique solution) using inverse of a matrix.

#### Continuity and Differentiability

Continuity and Differentiability – summary: Continuity and differentiability, derivative of composite functions, chain rule, derivatives of inverse trigonometric functions, derivative of implicit functions. Concept of exponential and logarithmic functions. Derivatives of logarithmic and exponential functions. Logarithmic differentiation, derivative of functions expressed in parametric forms. Second order derivatives. Rolle’s and Lagrange’s Mean Value Theorems (without proof) and their geometric interpretation.

#### Applications of Derivatives

Applications of Derivatives – summary: rate of change of bodies, increasing/decreasing functions, tangents and normals, use of derivatives in approximation, maxima and minima (first derivative test motivated geometrically and second derivative test given as a provable tool). Simple problems (that illustrate basic principles and understanding of the subject as well as real-life situations).

#### Integrals

Integrals – summary: Integration as inverse process of differentiation.Integration of a variety of functions by substitution, by partial fractions and by parts, Evaluation of simple integrals of the types given in the syllabus and problems based on them. Definite integrals as a limit of a sum, Fundamental Theorem of Calculus (without proof).Basic properties of definite integrals and evaluation of definite integrals.

#### Applications of the Integrals

Applications of the Integrals – summary: Applications in finding the area under simple curves, especially lines, circles/parabolas/ellipses (in standard form only), Area between any of the two above said curves (the region should be clearly identifiable).

#### Differential Equations

Differential Equations – summary: Definition, order and degree, general and particular solutions of a differential equation.Formation of differential equation whose general solution is given.Solution of differential equations by method of separation of variables solutions of homogeneous differential equations of first order and first degree. Solutions of linear differential equation of the type given in the syllabus.

#### Vectors

10 Vectors – summary: Vectors and scalars, magnitude and direction of a vector.Direction cosines and direction ratios of a vector. Types of vectors (equal, unit, zero, parallel and collinear vectors), position vector of a point, negative of a vector, components of a vector, addition of vectors, multiplication of a vector by a scalar, position vector of a point dividing a line segment in a given ratio. Definition, Geometrical Interpretation, properties and application of scalar (dot) product of vectors, vector (cross) product of vectors, scalar triple product of vectors.

#### Three – dimensional Geometry

11 Three – Dimensional Geometry – summary: Direction cosines and direction ratios of a line joining two points.Cartesian equation and vector equation of a line, coplanar and skew lines, shortest distance between two lines.Cartesian and vector equation of a plane.Angle between (i) two lines, (ii) two planes, (iii) a line and a plane.Distance of a point from a plane.

#### Linear Programming

12 Linear Programming – summary: Introduction, related terminology such as constraints, objective function, optimization, different types of linear programming (L.P.) problems, mathematical formulation of L.P. problems, graphical method of solution for problems in two variables, feasible and infeasible regions(bounded and unbounded), feasible and infeasible solutions, optimal feasible solutions (up to three non-trivial constraints).

#### Probability

13 Probability – summary: Conditional probability, multiplication theorem on probability, independent events, total probability, Bayes’ theorem, Random variable and its probability distribution, mean and variance of random variable. Repeated independent (Bernoulli) trials and Binomial distribution.

## Related Pages

Also see the complete solutions for NCERT (All Classes and Subjects).

#### मान लीजिए कि N में *, a * b = a तथा b का H.C.F. द्वारा परिभाषित द्विआधारी संक्रिया है। क्या * क्रमविनिमय है? क्या * साहचर्य है? क्या N में इस द्विआधारी संक्रिया के तत्समक का अस्तित्व है?

दिया है: N में *, a * b = a तथा b का H.C.F. द्वारा परिभाषित द्विआधारी संक्रिया है।
हम जानते हैं कि a और b का H.C.F. = b और a का H.C.F., सभी a, b ∈ N के लिए
∴ a * b = b * a, अतः, संक्रिया * क्रमविनिमय है।
सभी a, b, c ∈ N के लिए, (a * b)* c = (a और b का H.C.F.) * c = a, b और c का H.C.F.
तथा a *(b * c) = a *(b और c का H.C.F.) = a, b और c का H.C.F.
∴ (a * b) * c = a * (b * c), अतः, संक्रिया * साहचर्य है।
अब, कोई अवयव e ∈ N, संक्रिया * में तत्समक होगा यदि a * e = a = e* a, सभी a ∈ N के लिए
लेकिन ये संबंध किसी भी a ∈ N के लिए सत्य नहीं है।
अतः, N में इस द्विआधारी संक्रिया * के तत्समक का अस्तित्व नहीं है।

#### Show that the function f: R → R given by f(x) = x^3 is injective.

f: R → R is given as f(x) = x^3.
For one – one
Suppose f(x) = f(y), where x, y ∈ R.
⇒ x^3 = y^3 … (1)
Now, we need to show that x = y.
Suppose x ≠ y, their cubes will also not be equal.
⇒ x^3 ≠ y^3
However, this will be a contradiction to (1).
∴ x = y
Hence, f is injective.

#### निम्नलिखित को सिद्ध कीजिए: 3〖sin〗^(-1) x=〖sin〗^(-1) (3x-4x^3 ), x∈[-1/2,1/2].

माना, 〖sin〗^(-1) x = θ, तब x = sin θ.,
RHS = 〖sin〗^(-1) (3x-4x^3 )
=〖sin〗^(-1) (3 sin⁡θ-4〖sin〗^3 θ)
=〖sin〗^(-1) (sin⁡3θ )
= 3θ
= 3〖sin〗^(-1) x
= LHS

#### If A, B are symmetric matrices of same order, then what type of matrix AB – BA is?

(𝐴𝐵 − 𝐵𝐴)′=(𝐴𝐵)′ − (𝐵𝐴)′ [∵ (𝑋 − 𝑌)′=𝑋′−𝑌′] =𝐵′𝐴′ − 𝐴′𝐵′ [∵ (𝑋𝑌)′=𝑌′𝑋′] =𝐵𝐴 − 𝐴𝐵 [∵ Given: 𝐴′=𝐴,𝐵′=𝐵] =− (𝐴𝐵−𝐵𝐴)
⇒(𝐴𝐵 − 𝐵𝐴)′
=−(𝐴𝐵 − 𝐵𝐴),
Therefore,the matrix (AB − BA) is a skew symmetric matrix.

#### Which type of matrices have determinants?

Only square matrices have determinants.

#### फलन f(x)=x^2+2x-8,x∈[-4,2] के लिए रोले के प्रमेय को सत्यापित कीजिए।

दिया गया फलन f(x)=x^2+2x-8,x∈[-4,2] (i) फलन f एक बहुपद है। अतः, यह संवृत अंतराल [-4,2] में संतत है।
(ii) f'(x)=2x+2
अतः, फलन f विवृत अंतराल (-4,2) में अवकलनीय है।
(iii) f(-4)=(-4)^2+2(-4)-8=16-8-8=0
तथा f(2)=(2)^2+2(2)-8=4+4-8=0
⇒f(-4)=f(2)
यहाँ, रोले की तीनों परिस्थितियाँ सत्य हैं। इसलिए, विवृत अंतराल (-4,2) में किसी ऐसे c का अस्तित्व है कि f'(c)=0 है।
⇒f^’ (c)=2c+2=0
⇒c=-1∈(-4,2)
अतः, फलन f(x)=x^2+2x-8,x∈[-4,2] के लिए रोले की प्रमेय सत्यापित हो जाती है।

#### Find two positive numbers whose sum is 16 and the sum of whose cubes is minimum.

Let one number be x. Then, the other number is (16 − x).
Let the sum of the cubes of these numbers be denoted by S(x). Then,
⇒S(x)=x^3+(16-x)^3
∴〖 S〗^’ (x)=3x^2-3(16-x)^2, S^” (x)=6x+6(16-x)
Now, S^’ (x)=0
⇒ 3x^2-3(16-x)^2 = 0
⇒ x^2-(16-x)^2=0
⇒ x^2-256-x^2+32x = 0
⇒ x = 256/32 = 8
Now S^” (8)=6(8)+6(16-8)=48+48=96>0
∴ By second derivative test, x = 8 is the point of local minima of S.
Hence, the sum of the cubes of the numbers is the minimum when the numbers are 8 and 16 − 8 = 8.

#### Find the point on the curve y = x3 – 11x + 5 at which the tangent is y = x – 11.

The slope of tangent to the curve y=x^3-11x+5 is dy/dx=3x^2-11
Slope of the line y=x-11 is 1.
Given that:
The slope of tangent to the curve y=x^3-11x+5 = the slope of the line y=x-11
⇒2x^2-11=1
⇒3x^2=12
⇒x^2=4
⇒x=±2
If x=2, then y=(2)^3-11(2)+5=-9, therefore, the point = (2,-9)
If x=-2, then y=(-2)^3-11(-2)+5=18, therefore, the point = (-2,19)
Out of the points (2,-9) and (-2,19), only (2,-9) satisfy the equation of line y=x-11.
Hence, (2,-9) is the point on y=x^3-11x+5 at which tangent is y=x-11.

#### What is integration?

The formula that gives all anti derivatives is called the indefinite integral of the function and such
process of finding anti derivatives is called integration.

#### Fill in the blank: The area of the region bounded by the curve x = y2, y-axis and the line y = 3 and y = 4 is _______.

37/3 square units.

#### What is different between a general solutions and a particular solutions.

A relation between involved variables, which satisfy the given differential equation is called its solution. The solution which contains as many arbitrary constants as the order of the differential equation is called the general solution and the solution free from arbitrary constants is called particular solution.

#### How do you find the dot product of two vectors a and b?

The scalar or dot product of two given vectors a and b having an angle θ between them is defined as a.b = |a||b|cos θ.

#### Find the Equation of a plane which is at a distance p from the origin with direction cosines of the normal to the plane as l, m, n.

Equation of a plane which is at a distance p from the origin with direction cosines of the normal to the plane as l, m, n is lx + my + nz = p.

#### What do you understand by LPP?

A linear programming problem (LPP) deals with the optimisation (maximisation/minimisation) of a linear function of two variables (say x and y) known as objective function subject to the conditions that the variables are non-negative and satisfy a set of linear inequalities (called linear constraints).

#### What are independent events?

Let E and F be two events associated with a sample space S. If the probability of occurrence of one of them is not affected by the occurrence of the other, then the two events are independent.

## 11 thoughts on “NCERT Solutions for Class 12 Maths”

1. gautam kumar says:

very good

1. suman kumar says:

Very good

2. Abhishek says:

Sir kya 12th math ka hindi medium me kuch chapter ka hindi medium notes nahi hai…..and phy che bio ka bhi hindi medium solution nahi hai… please upload

3. mac says:

sir chapter 1 me hindi solution me download ka option nhi h

4. mac says:

12th class me

5. Asgar Husain says:

6. studiestoday says:

Very nice sites for helping class 10-12 students for practicing sample papers to help them score higher in board exams. i love how you maintain quality content and regular updates new question papers.

7. Rupesh Singh Rathore says:

sir please hindi mediam me mathematics ki pdf banaeye

8. anjali srivastav says:

this site is really very good and helpful .

9. Amrish verma says:

thanks

10. Amrish verma says:

excellent