Mathematics · Class 11 Science
Ch 7Matrices — Class 11 Mathematics, concept-first.
The idea of matrices grew directly out of a practical need: a compact, efficient way to solve systems of linear equations. Writing the coefficients of several equations as a single rectangular block turned out to be far more convenient — and far more powerful — than working through elimination by hand, equation by equa…
Key concepts
Hover a concept to preview it and jump to its most relevant Q&A.
Matrix Notation
You run a fruit stall selling apples, bananas, and oranges, and you track sales across Monday, Tuesday, and Wednesday. You could write three separate lists:
Most relevant Q&A
- In the matrix $A = \begin{bmatrix} 2 & 5 & 19 & -7 \\ 35 & -2 & \frac{5}{2} & 12 \\ \sqrt{3} & 1 & -5 & 17 \end{bmatrix}$, write: (i) The or…Free
- Consider the following information regarding the number of men and women workers in three factories I, II and III. Men workers / Women worke…Free
- In the matrix $A = \begin{bmatrix} a & 1 & x \\ 2 & \sqrt{3} & x^2 - y \\ 0 & 5 & -\frac{2}{5} \end{bmatrix}$, write: (i) The order of the m…Free
- If $\begin{bmatrix} 2x+y & 4x \\ 5x-7 & 4x \end{bmatrix} = \begin{bmatrix} 7 & 7y-13 \\ y & x+6 \end{bmatrix}$, then the value of $x + y$ is…Preview
- A matrix denotes a number.Preview
In previous exams
How often this chapter’s concepts have been examined — real appearance data, never estimated.
Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
Introduction
The idea of matrices grew directly out of a practical need: a compact, efficient way to solve systems of linear equations.
Matrix
A matrix organises information in a rectangular arrangement. To record that Radha has 15 notebooks you could write ; if she also has 6 pens, , with the first number meaning notebooks and the second pe…
Order of a Matrix
The order of a matrix describes its shape: how many rows and how many columns it has.
+−Worked Examplesi3 questions
- Example 1Consider the following information regarding the number of men and women workers in three factories I, II and III. Men workers / Women worke…Free
- Example 2If a matrix has $8$ elements, what are the possible orders it can have?Preview
- Example 3Construct a $3 \times 2$ matrix whose elements are given by $a_{ij} = \frac{1}{2}\,|\,i - 3j\,|$.Preview
Types of Matrices
Matrices come in several forms, each defined by its shape or the pattern of its entries. Different operations and properties apply to different kinds, so we examine each type, from the simplest shapes…
Equality of Matrices
12 QTwo matrices are equal only when they are identical in every respect — a strict condition, not mere similarity of shape. For two matrices and to be equal, two conditions must hold simultaneously.
+−Worked Examplesi2 questions
- Example 4If $\begin{bmatrix} x+3 & z+4 & 2y-7 \\ -6 & a-1 & 0 \\ b-3 & -21 & 0 \end{bmatrix} = \begin{bmatrix} 0 & 6 & 3y-2 \\ -6 & -3 & 2c+2 \\ 2b+4…Free
- Example 5Find the values of $a, b, c,$ and $d$ from the following equation: $\begin{bmatrix} 2a+b & a-2b \\ 5c-d & 4c+3d \end{bmatrix} = \begin{bmatr…Preview
+−Exercise 3.1i10 questions
- Q1In the matrix $A = \begin{bmatrix} 2 & 5 & 19 & -7 \\ 35 & -2 & \frac{5}{2} & 12 \\ \sqrt{3} & 1 & -5 & 17 \end{bmatrix}$, write: (i) The or…Free
- Q2If a matrix has 24 elements, what are the possible orders it can have? What, if it has 13 elements?Free
- Q3If a matrix has 18 elements, what are the possible orders it can have? What, if it has 5 elements?Free
- Q4Construct a $2 \times 2$ matrix, $A = [a_{ij}]$, whose elements are given by: (i) $a_{ij} = \frac{(i+j)^2}{2}$ (ii) $a_{ij} = \frac{i}{j}$ (…Preview
- Q5Construct a $3 \times 4$ matrix, whose elements are given by: (i) $a_{ij} = \frac{1}{2} |-3i+j|$ (ii) $a_{ij} = 2i-j$Preview
- Q6Find the values of $x, y$ and $z$ from the following equations: (i) $\begin{bmatrix} 4 & 3 \\ x & 5 \end{bmatrix} = \begin{bmatrix} y & z \\…Preview
- Q7Find the value of $a, b, c$ and $d$ from the equation: $\begin{bmatrix} a-b & 2a+c \\ 2a-b & 3c+d \end{bmatrix} = \begin{bmatrix} -1 & 5 \\…Preview
- Q8A = $[a_{ij}]_{m \times n}$ is a square matrix, if (A) $m < n$ (B) $m > n$ (C) $m = n$ (D) None of thesePreview
- Q9Which of the given values of $x$ and $y$ make the following pair of matrices equal $\begin{bmatrix} 3x+7 & 5 \\ y+1 & 2-3x \end{bmatrix}$, $…Preview
- Q10Find the value of the following: The number of all possible matrices of order $3 \times 3$ with each entry 0 or 1 is: (A) 27 (B) 18 (C) 81 (…Preview
Operations on Matrices
Matrices are not just static arrays of numbers; they can be combined and transformed. This section introduces the fundamental operations on matrices — addition, subtraction, scalar multiplication, and…
Addition of Matrices
Consider a manufacturer, Fatima, who owns two factories — one at location A and another at location B.
Multiplication of a Matrix by a Scalar
When a factory doubles its output, every entry in the production matrix is multiplied by 2. This operation — multiplying every element of a matrix by a fixed number — is called scalar multiplication.
Properties of Matrix Addition
Matrix addition is the operation of adding two matrices by adding their corresponding entries. For this to be defined, both matrices must be of the same order. If and are both matrices, then
Properties of Scalar Multiplication of a Matrix
Scalar multiplication of a matrix follows algebraic laws that mirror the properties of scalar multiplication in ordinary arithmetic.
+−Worked Examplesi4 questions
- Example 8If $A = \begin{bmatrix} 8 & 0 \\ 4 & -2 \\ 3 & 6 \end{bmatrix}$ and $B = \begin{bmatrix} 2 & -2 \\ 4 & 2 \\ -5 & 1 \end{bmatrix}$, then find…Free
- Example 9Find $X$ and $Y$, if $X + Y = \begin{bmatrix} 5 & 2 \\ 0 & 9 \end{bmatrix}$ and $X - Y = \begin{bmatrix} 3 & 6 \\ 0 & -1 \end{bmatrix}$.Free
- Example 10Find the values of $x$ and $y$ from the following equation: $2\begin{bmatrix} x & 5 \\ 7 & y-3 \end{bmatrix} + \begin{bmatrix} 3 & -4 \\ 1 &…Preview
- Example 11Two farmers Ramkishan and Gurcharan Singh cultivates only three varieties of rice namely Basmati, Permal and Naura. The sale (in Rupees) of…Preview
Multiplication of Matrices
Meera wants 2 pens and 5 story books; Nadeem needs 8 pens and 10 story books. At the first shop a pen costs ₹5 and a story book ₹50, so Meera needs rupees and Nadeem rupees.
+−Worked Examplesi4 questions
- Example 12Find $AB$, if $A = \begin{bmatrix} 6 & 9 \\ 2 & 3 \end{bmatrix}$ and $B = \begin{bmatrix} 2 & 6 & 0 \\ 7 & 9 & 8 \end{bmatrix}$.Free
- Example 13If $A = \begin{bmatrix} 1 & -2 & 3 \\ -4 & 2 & 5 \end{bmatrix}$ and $B = \begin{bmatrix} 2 & 3 \\ 4 & 5 \\ 2 & 1 \end{bmatrix}$, then find $…Free
- Example 14If $A = \begin{bmatrix} 1 & 0 \\ 0 & -1 \end{bmatrix}$ and $B = \begin{bmatrix} 0 & 1 \\ 1 & 0 \end{bmatrix}$, find $AB$ and $BA$, and show…Preview
- Example 15Find $AB$, if $A = \begin{bmatrix} 0 & -1 \\ 0 & 2 \end{bmatrix}$ and $B = \begin{bmatrix} 3 & 5 \\ 0 & 0 \end{bmatrix}$.Preview
Properties of Multiplication of Matrices
26 QMatrix multiplication follows algebraic rules similar to — but not identical with — those for real numbers. The key difference is that it is not commutative: in general, .
+−Worked Examplesi4 questions
- Example 16If $A = \begin{bmatrix} 1 & 1 & -1 \\ 2 & 0 & 3 \\ 3 & -1 & 2 \end{bmatrix}$, $B = \begin{bmatrix} 1 & 3 \\ 0 & 2 \\ -1 & 4 \end{bmatrix}$ a…Free
- Example 17If $A = \begin{bmatrix} 0 & 6 & 7 \\ -6 & 0 & 8 \\ 7 & -8 & 0 \end{bmatrix}$, $B = \begin{bmatrix} 0 & 1 & 1 \\ 1 & 0 & 2 \\ 1 & 2 & 0 \end{…Free
- Example 18If $A = \begin{bmatrix} 1 & 2 & 3 \\ 3 & -2 & 1 \\ 4 & 2 & 1 \end{bmatrix}$, then show that $A^3 - 23A - 40I = O$.Preview
- Example 19In a legislative assembly election, a political group hired a public relations firm to promote its candidate in three ways: telephone, house…Preview
+−Exercise 3.2i22 questions
- Q1Let $A = \begin{bmatrix} 2 & 4 \\ 3 & 2 \end{bmatrix}$, $B = \begin{bmatrix} 1 & 3 \\ -2 & 5 \end{bmatrix}$, $C = \begin{bmatrix} -2 & 5 \\…Free
- Q2Compute the following: (i) $\begin{bmatrix} a & b \\ -b & a \end{bmatrix} + \begin{bmatrix} a & b \\ b & a \end{bmatrix}$ (ii) $\begin{bmatr…Free
- Q3Compute the indicated products. (i) $\begin{bmatrix} a & b \\ -b & a \end{bmatrix} \begin{bmatrix} a & -b \\ b & a \end{bmatrix}$ (ii) $\beg…Free
- Q4If $A = \begin{bmatrix} 1 & 2 & -3 \\ 5 & 0 & 2 \\ 1 & -1 & 1 \end{bmatrix}$, $B = \begin{bmatrix} 3 & -1 & 2 \\ 4 & 2 & 5 \\ 2 & 0 & 3 \end…Preview
- Q5If $A = \begin{bmatrix} \frac{2}{3} & 1 & \frac{5}{3} \\ \frac{1}{3} & \frac{2}{3} & \frac{4}{3} \\ \frac{7}{3} & 2 & \frac{2}{3} \end{bmatr…Preview
- Q6Simplify $\cos\theta \begin{bmatrix} \cos\theta & \sin\theta \\ -\sin\theta & \cos\theta \end{bmatrix} + \sin\theta \begin{bmatrix} \sin\the…Preview
- Q7Find X and Y, if (i) $X+Y = \begin{bmatrix} 7 & 0 \\ 2 & 5 \end{bmatrix}$ and $X-Y = \begin{bmatrix} 3 & 0 \\ 0 & 3 \end{bmatrix}$. (ii) $2X…Preview
- Q8Find X, if $Y = \begin{bmatrix} 3 & 2 \\ 1 & 4 \end{bmatrix}$ and $2X+Y = \begin{bmatrix} 1 & 0 \\ -3 & 2 \end{bmatrix}$.Preview
- Q9Find $x$ and $y$, if $2 \begin{bmatrix} 1 & 3 \\ 0 & x \end{bmatrix} + \begin{bmatrix} y & 0 \\ 1 & 2 \end{bmatrix} = \begin{bmatrix} 5 & 6…Preview
- Q10Solve the equation for $x, y, z$ and $t$, if $2 \begin{bmatrix} x & z \\ y & t \end{bmatrix} + 3 \begin{bmatrix} 1 & -1 \\ 0 & 2 \end{bmatri…Preview
- Q11If $x \begin{bmatrix} 2 \\ 3 \end{bmatrix} + y \begin{bmatrix} -1 \\ 1 \end{bmatrix} = \begin{bmatrix} 10 \\ 5 \end{bmatrix}$, find the valu…Preview
- Q12Given $3 \begin{bmatrix} x & y \\ z & w \end{bmatrix} = \begin{bmatrix} x & 6 \\ -1 & 2w \end{bmatrix} + \begin{bmatrix} 4 & x+y \\ z+w & 3…Preview
- Q13If $F(x) = \begin{bmatrix} \cos x & -\sin x & 0 \\ \sin x & \cos x & 0 \\ 0 & 0 & 1 \end{bmatrix}$, show that $F(x) F(y) = F(x+y)$.Preview
- Q14Show that (i) $\begin{bmatrix} 5 & -1 \\ 6 & 7 \end{bmatrix} \begin{bmatrix} 2 & 1 \\ 3 & 4 \end{bmatrix} \neq \begin{bmatrix} 2 & 1 \\ 3 &…Preview
- Q15Find $A^2 - 5A + 6I$, if $A = \begin{bmatrix} 2 & 0 & 1 \\ 2 & 1 & 3 \\ 1 & -1 & 0 \end{bmatrix}$.Preview
- Q16If $A = \begin{bmatrix} 1 & 0 & 2 \\ 0 & 2 & 1 \\ 2 & 0 & 3 \end{bmatrix}$, prove that $A^3 - 6A^2 + 7A + 2I = 0$.Preview
- Q17If $A = \begin{bmatrix} 3 & -2 \\ 4 & -2 \end{bmatrix}$ and $I = \begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix}$, find $k$ so that $A^2 = kA -…Preview
- Q18If $A = \begin{bmatrix} 0 & -\tan \frac{\alpha}{2} \\ \tan \frac{\alpha}{2} & 0 \end{bmatrix}$ and $I$ is the identity matrix of order 2, sh…Preview
- Q19A trust fund has ₹ 30,000 that must be invested in two different types of bonds. The first bond pays 5% interest per year, and the second bo…Preview
- Q20The bookshop of a particular school has 10 dozen chemistry books, 8 dozen physics books, 10 dozen economics books. Their selling prices are…Preview
- Q21Assume $X$, $Y$, $Z$, $W$ and $P$ are matrices of order $2 \times n$, $3 \times k$, $2 \times p$, $n \times 3$ and $p \times k$, respectivel…Preview
- Q22Assume $X$, $Y$, $Z$, $W$ and $P$ are matrices of order $2 \times n$, $3 \times k$, $2 \times p$, $n \times 3$ and $p \times k$, respectivel…Preview
Transpose of a Matrix
A natural operation on a matrix is to flip it — turning rows into columns and columns into rows. This is called transposition, and the result is the transpose of the original.
Properties of Transpose of the Matrices
The transpose of a matrix is a fundamental operation that swaps its rows and columns. If a matrix has entry in the -th row and -th column, then its transpose, denoted (or ), has the entry in the -th r…
+−Worked Examplesi2 questions
- Example 20If $A = \begin{bmatrix} 3 & 3 & 2 \\ 4 & 2 & 0 \end{bmatrix}$ and $B = \begin{bmatrix} 2 & -1 & 2 \\ 1 & 2 & 4 \end{bmatrix}$, verify that (…Free
- Example 21If $A = \begin{bmatrix} -2 \\ 4 \\ 5 \end{bmatrix}$, $B = \begin{bmatrix} 1 & 3 & -6 \end{bmatrix}$, verify that $(AB)' = B'A'$.Preview
Symmetric and Skew Symmetric Matrices
13 QA square matrix can have special symmetry properties that simplify calculations and reveal structure. The two fundamental types are symmetric and skew symmetric matrices.
+−Worked Examplesi1 question
+−Exercise 3.3i12 questions
- Q1Find the transpose of each of the following matrices: (i) $\begin{bmatrix} 5 \\ \frac{1}{2} \\ -1 \end{bmatrix}$ (ii) $\begin{bmatrix} 1 & -…Free
- Q2If $A = \begin{bmatrix} -1 & 2 & 3 \\ 5 & 7 & 9 \\ -2 & 1 & 1 \end{bmatrix}$ and $B = \begin{bmatrix} -4 & 1 & -5 \\ 1 & 2 & 0 \\ 1 & 3 & 1…Free
- Q3If $A' = \begin{bmatrix} 3 & 4 \\ -1 & 2 \\ 0 & 1 \end{bmatrix}$ and $B = \begin{bmatrix} -1 & 2 & 1 \\ 1 & 2 & 3 \end{bmatrix}$, then verif…Free
- Q4If $A' = \begin{bmatrix} -2 & 3 \\ 1 & 2 \end{bmatrix}$ and $B = \begin{bmatrix} -1 & 0 \\ 1 & 2 \end{bmatrix}$, then find $(A + 2B)'$Preview
- Q5For the matrices A and B, verify that $(AB)' = B'A'$, where (i) $A = \begin{bmatrix} 1 \\ -4 \\ 3 \end{bmatrix}$, $B = \begin{bmatrix} -1 &…Preview
- Q6If (i) $A = \begin{bmatrix} \cos \alpha & \sin \alpha \\ -\sin \alpha & \cos \alpha \end{bmatrix}$, then verify that $A'A = I$ (ii) If $A =…Preview
- Q7(i) Show that the matrix $A = \begin{bmatrix} 1 & -1 & 5 \\ -1 & 2 & 1 \\ 5 & 1 & 3 \end{bmatrix}$ is a symmetric matrix. (ii) Show that the…Preview
- Q8For the matrix $A = \begin{bmatrix} 1 & 5 \\ 6 & 7 \end{bmatrix}$, verify that (i) $(A + A')$ is a symmetric matrix (ii) $(A - A')$ is a ske…Preview
- Q9Find $\frac{1}{2}(A + A')$ and $\frac{1}{2}(A - A')$, when $A = \begin{bmatrix} 0 & a & b \\ -a & 0 & c \\ -b & -c & 0 \end{bmatrix}$Preview
- Q10Express the following matrices as the sum of a symmetric and a skew symmetric matrix: (i) $\begin{bmatrix} 3 & 5 \\ 1 & -1 \end{bmatrix}$ (i…Preview
- Q11If $A$, $B$ are symmetric matrices of same order, then $AB - BA$ is a (A) Skew symmetric matrix (B) Symmetric matrix (C) Zero matrix (D) Ide…Preview
- Q12If $A = \begin{bmatrix} \cos \alpha & -\sin \alpha \\ \sin \alpha & \cos \alpha \end{bmatrix}$, and $A + A' = I$, then the value of $\alpha$…Preview
Invertible Matrices
Every non-zero number has a reciprocal, whose product with the number is 1. For matrices there is an analogous idea: the inverse of a square matrix, whose product with the matrix is the identity matri…
Miscellaneous Examples
+−Miscellaneous Examplesi3 questions
- Example 23If $A = \begin{bmatrix} \cos\theta & \sin\theta \\ -\sin\theta & \cos\theta \end{bmatrix}$, then prove that $A^n = \begin{bmatrix} \cos n\th…Free
- Example 24If $A$ and $B$ are symmetric matrices of the same order, then show that $AB$ is symmetric if and only if $A$ and $B$ commute, that is $AB =…Preview
- Example 25Let $A = \begin{bmatrix} 2 & -1 \\ 3 & 4 \end{bmatrix}$, $B = \begin{bmatrix} 5 & 2 \\ 7 & 4 \end{bmatrix}$, $C = \begin{bmatrix} 2 & 5 \\ 3…Preview
Miscellaneous Exercise on Chapter 3
+−Miscellaneous Exercisei11 questions
- Q1If $A$ and $B$ are symmetric matrices, prove that $AB - BA$ is a skew symmetric matrix.Free
- Q2Show that the matrix $B'AB$ is symmetric or skew symmetric according as $A$ is symmetric or skew symmetric.Free
- Q3Find the values of $x, y, z$ if the matrix $A = \begin{bmatrix} 0 & 2y & z \\ x & y & -z \\ x & -y & z \end{bmatrix}$ satisfy the equation $…Free
- Q4Find the value of the following: For what values of $x : \begin{bmatrix} 1 & 2 & 1 \end{bmatrix} \begin{bmatrix} 1 & 2 & 0 \\ 2 & 0 & 1 \\ 1…Preview
- Q5If $A = \begin{bmatrix} 3 & 1 \\ -1 & 2 \end{bmatrix}$, show that $A^2 - 5A + 7I = 0$.Preview
- Q6Find $x$, if $\begin{bmatrix} x & -5 & -1 \end{bmatrix} \begin{bmatrix} 1 & 0 & 2 \\ 0 & 2 & 1 \\ 2 & 0 & 3 \end{bmatrix} \begin{bmatrix} x…Preview
- Q7A manufacturer produces three products $x, y, z$ which he sells in two markets. Annual sales are indicated below: Market I — $x$: 10,000, $y…Preview
- Q8Find the matrix $X$ so that $X\begin{bmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \end{bmatrix} = \begin{bmatrix} -7 & -8 & -9 \\ 2 & 4 & 6 \end{bmatrix}…Preview
- Q9If $A = \begin{bmatrix} \alpha & \beta \\ \gamma & -\alpha \end{bmatrix}$ is such that $A^2 = I$, then (A) $1 + \alpha^2 + \beta\gamma = 0$…Preview
- Q10If the matrix $A$ is both symmetric and skew symmetric, then (A) $A$ is a diagonal matrix (B) $A$ is a zero matrix (C) $A$ is a square matri…Preview
- Q11If A is square matrix such that $A^2 = A$, then $(I + A)^3 - 7A$ is equal to (A) A (B) $I - A$ (C) I (D) $3A$Preview
Summary
- A matrix is a rectangular array of numbers arranged in rows and columns, denoted as . - Order of a matrix is ; two matrices are equal only if they have the same order and corresponding elements are…
Exemplar Problems
Higher-order thinking / exemplar-style practice problems.
+−Show 96 questionsHide questions96 questions
- Q1If a matrix has 28 elements, what are the possible orders it can have? What if it has 13 elements?Free
- Q2In the matrix $A = \begin{bmatrix} a & 1 & x \\ 2 & \sqrt{3} & x^2 - y \\ 0 & 5 & -\frac{2}{5} \end{bmatrix}$, write: (i) The order of the m…Free
- Q3Construct a $2 \times 2$ matrix where (i) $a_{ij} = \dfrac{(i-2j)^2}{2}$ (ii) $a_{ij} = |-2i+3j|$Free
- Q4Construct a $3 \times 2$ matrix whose elements are given by $a_{ij} = e^{ix}\sin jx$.Preview
- Q5Find values of $a$ and $b$ if $A = B$, where $A = \begin{bmatrix} a+4 & 3b \\ 8 & -6 \end{bmatrix}$, $B = \begin{bmatrix} 2a+2 & b^2+2 \\ 8…Preview
- Q6If possible, find the sum of the matrices $A$ and $B$, where $A = \begin{bmatrix} \sqrt{3} & 1 \\ 2 & 3 \end{bmatrix}$, and $B = \begin{bmat…Preview
- Q7If $X = \begin{bmatrix} 3 & 1 & -1 \\ 5 & -2 & -3 \end{bmatrix}$ and $Y = \begin{bmatrix} 2 & 1 & -1 \\ 7 & 2 & 4 \end{bmatrix}$, find (i) $…Preview
- Q8Find non-zero values of $x$ satisfying the matrix equation: $x\begin{bmatrix} 2x & 2 \\ 3 & x \end{bmatrix} + 2\begin{bmatrix} 8 & 5x \\ 4 &…Preview
- Q9If $A = \begin{bmatrix} 0 & 1 \\ 1 & 1 \end{bmatrix}$ and $B = \begin{bmatrix} 0 & -1 \\ 1 & 0 \end{bmatrix}$, show that $(A + B)(A - B) \ne…Preview
- Q10Find the value of $x$ if $\begin{bmatrix} 1 & x & 1 \end{bmatrix}\begin{bmatrix} 1 & 3 & 2 \\ 2 & 5 & 1 \\ 15 & 3 & 2 \end{bmatrix}\begin{bm…Preview
- Q11Show that $A = \begin{bmatrix} 5 & 3 \\ -1 & -2 \end{bmatrix}$ satisfies the equation $A^2 - 3A - 7I = O$ and hence find $A^{-1}$.Preview
- Q12Find the matrix $A$ satisfying the matrix equation: $\begin{bmatrix} 2 & 1 \\ 3 & 2 \end{bmatrix} A \begin{bmatrix} -3 & 2 \\ 5 & -3 \end{bm…Preview
- Q13Find $A$, if $\begin{bmatrix} 4 \\ 1 \\ 3 \end{bmatrix} A = \begin{bmatrix} -4 & 8 & 4 \\ -1 & 2 & 1 \\ -3 & 6 & 3 \end{bmatrix}$.Preview
- Q14If $A = \begin{bmatrix} 3 & -4 \\ 1 & 1 \\ 2 & 0 \end{bmatrix}$ and $B = \begin{bmatrix} 2 & 1 & 2 \\ 1 & 2 & 4 \end{bmatrix}$, then verify…Preview
- Q15If possible, find $BA$ and $AB$, where $A = \begin{bmatrix} 2 & 1 & 2 \\ 1 & 2 & 4 \end{bmatrix}$, $B = \begin{bmatrix} 4 & 1 \\ 2 & 3 \\ 1…Preview
- Q16Show by an example that for $A \neq O$, $B \neq O$, $AB = O$.Preview
- Q17Given $A = \begin{bmatrix} 2 & 4 & 0 \\ 3 & 9 & 6 \end{bmatrix}$ and $B = \begin{bmatrix} 1 & 4 \\ 2 & 8 \\ 1 & 3 \end{bmatrix}$. Is $(AB)'…Preview
- Q18Solve for $x$ and $y$: $x\begin{bmatrix} 2 \\ 1 \end{bmatrix} + y\begin{bmatrix} 3 \\ 5 \end{bmatrix} + \begin{bmatrix} -8 \\ -11 \end{bmatr…Preview
- Q19If $X$ and $Y$ are $2 \times 2$ matrices, then solve the following matrix equations for $X$ and $Y$: $2X + 3Y = \begin{bmatrix} 2 & 3 \\ 4 &…Preview
- Q20If $A = \begin{bmatrix} 3 & 5 \end{bmatrix}$, $B = \begin{bmatrix} 7 & 3 \end{bmatrix}$, then find a non-zero matrix $C$ such that $AC = BC$…Preview
- Q21Give an example of matrices $A$, $B$ and $C$ such that $AB = AC$, where $A$ is a non-zero matrix, but $B \neq C$.Preview
- Q22If $A = \begin{bmatrix} 1 & 2 \\ -2 & 1 \end{bmatrix}$, $B = \begin{bmatrix} 2 & 3 \\ 3 & -4 \end{bmatrix}$ and $C = \begin{bmatrix} 1 & 0 \…Preview
- Q23If $P = \begin{bmatrix} x & 0 & 0 \\ 0 & y & 0 \\ 0 & 0 & z \end{bmatrix}$ and $Q = \begin{bmatrix} a & 0 & 0 \\ 0 & b & 0 \\ 0 & 0 & c \end…Preview
- Q24If $\begin{bmatrix} 2 & 1 & 3 \end{bmatrix}\begin{bmatrix} -1 & 0 & -1 \\ -1 & 1 & 0 \\ 0 & 1 & 1 \end{bmatrix}\begin{bmatrix} 1 \\ 0 \\ -1…Preview
- Q25If $A = \begin{bmatrix}2 & 1\end{bmatrix}$, $B = \begin{bmatrix}5 & 3 & 4\\ 8 & 7 & 6\end{bmatrix}$ and $C = \begin{bmatrix}-1 & 2 & 1\\ 1 &…Preview
- Q26If $A = \begin{bmatrix}1 & 0 & -1\\ 2 & 1 & 3\\ 0 & 1 & 1\end{bmatrix}$, then verify that $A^2 + A = A(A + I)$, where $I$ is the $3 \times 3…Preview
- Q27If $A = \begin{bmatrix}0 & -1 & 2\\ 4 & 3 & -4\end{bmatrix}$ and $B = \begin{bmatrix}4 & 0\\ 1 & 3\\ 2 & 6\end{bmatrix}$, then verify that:…Preview
- Q28If $A = \begin{bmatrix}1 & 2\\ 4 & 1\\ 5 & 6\end{bmatrix}$ and $B = \begin{bmatrix}1 & 2\\ 6 & 4\\ 7 & 3\end{bmatrix}$, then verify that: (i…Preview
- Q29Show that $A'A$ and $AA'$ are both symmetric matrices for any matrix $A$.Preview
- Q30Let $A$ and $B$ be square matrices of the order $3 \times 3$. Is $(AB)^2 = A^2 B^2$? Give reasons.Preview
- Q31Show that if $A$ and $B$ are square matrices such that $AB = BA$, then $(A + B)^2 = A^2 + 2AB + B^2$.Preview
- Q32Let $A = \begin{bmatrix}1 & 2\\ -1 & 3\end{bmatrix}$, $B = \begin{bmatrix}4 & 0\\ 1 & 5\end{bmatrix}$, $C = \begin{bmatrix}2 & 0\\ 1 & -2\en…Preview
- Q33If $A = \begin{bmatrix}\cos\theta & \sin\theta\\ -\sin\theta & \cos\theta\end{bmatrix}$, then show that $A^2 = \begin{bmatrix}\cos 2\theta &…Preview
- Q34If $A = \begin{bmatrix}0 & -x\\ x & 0\end{bmatrix}$, $B = \begin{bmatrix}0 & 1\\ 1 & 0\end{bmatrix}$ and $x^2 = -1$, then show that $(A + B)…Preview
- Q35Verify that $A^2 = I$ when $A = \begin{bmatrix}0 & 1 & -1\\ 4 & -3 & 4\\ 3 & -3 & 4\end{bmatrix}$.Preview
- Q36Prove by Mathematical Induction that $(A')^n = (A^n)'$, where $n \in \mathbb{N}$ for any square matrix $A$.Preview
- Q37If $\begin{bmatrix}xy & 4\\ z+6 & x+y\end{bmatrix} = \begin{bmatrix}8 & w\\ 0 & 6\end{bmatrix}$, then find values of $x$, $y$, $z$ and $w$.Preview
- Q38If $A = \begin{bmatrix}1 & 5\\ 7 & 12\end{bmatrix}$ and $B = \begin{bmatrix}9 & 1\\ 7 & 8\end{bmatrix}$, find a matrix $C$ such that $3A + 5…Preview
- Q39If $A = \begin{bmatrix}3 & -5\\ -4 & 2\end{bmatrix}$, then find $A^2 - 5A - 14I$. Hence, obtain $A^3$.Preview
- Q40Find the values of $a$, $b$, $c$ and $d$, if $3\begin{bmatrix}a & b\\ c & d\end{bmatrix} = \begin{bmatrix}a & 6\\ -1 & 2d\end{bmatrix} + \be…Preview
- Q41Find the matrix $A$ such that $\begin{bmatrix}2 & -1\\ 1 & 0\\ -3 & 4\end{bmatrix} A = \begin{bmatrix}-1 & -8 & -10\\ 1 & -2 & -5\\ 9 & 22 &…Preview
- Q42If $A = \begin{bmatrix}1 & 2\\ 4 & 1\end{bmatrix}$, find $A^2 + 2A + 7I$.Preview
- Q43If $A = \begin{bmatrix}\cos\alpha & \sin\alpha\\ -\sin\alpha & \cos\alpha\end{bmatrix}$, and $A^{-1} = A'$, find value of $\alpha$.Preview
- Q44If the matrix $\begin{bmatrix}0 & a & 3\\ 2 & b & -1\\ c & 1 & 0\end{bmatrix}$ is a skew symmetric matrix, find the values of $a$, $b$ and $…Preview
- Q45If $P(x) = \begin{bmatrix}\cos x & \sin x\\ -\sin x & \cos x\end{bmatrix}$, then show that $P(x) \cdot P(y) = P(x + y) = P(y) \cdot P(x)$.Preview
- Q46If $A$ is square matrix such that $A^2 = A$, show that $(I + A)^3 = 7A + I$.Preview
- Q47If $A$, $B$ are square matrices of same order and $B$ is a skew-symmetric matrix, show that $A'BA$ is skew symmetric.Preview
- Q48If $AB = BA$ for any two square matrices, prove by mathematical induction that $(AB)^n = A^n B^n$.Preview
- Q49Find $x$, $y$, $z$ if $A = \begin{bmatrix} 0 & 2y & z \\ x & y & -z \\ x & -y & z \end{bmatrix}$ satisfies $A' = A^{-1}$.Preview
- Q50Express the matrix $\begin{bmatrix} 2 & 3 & 1 \\ 1 & -1 & 2 \\ 4 & 1 & 2 \end{bmatrix}$ as the sum of a symmetric and a skew symmetric matri…Preview
- Q51The matrix $P = \begin{bmatrix} 0 & 0 & 4 \\ 0 & 4 & 0 \\ 4 & 0 & 0 \end{bmatrix}$ is a (A) square matrix (B) diagonal matrix (C) unit matri…Preview
- Q52Total number of possible matrices of order $3 \times 3$ with each entry $2$ or $0$ is (A) $9$ (B) $27$ (C) $81$ (D) $512$Preview
- Q53If $\begin{bmatrix} 2x+y & 4x \\ 5x-7 & 4x \end{bmatrix} = \begin{bmatrix} 7 & 7y-13 \\ y & x+6 \end{bmatrix}$, then the value of $x + y$ is…Preview
- Q54If $A = \dfrac{1}{\pi}\begin{bmatrix} \sin^{-1}(\pi x) & \tan^{-1}\left(\dfrac{x}{\pi}\right) \\ \sin^{-1}\left(\dfrac{x}{\pi}\right) & \cot…Preview
- Q55If $A$ and $B$ are two matrices of the order $3 \times m$ and $3 \times n$, respectively, and $m = n$, then the order of matrix $(5A - 2B)$…Preview
- Q56If $A = \begin{bmatrix} 0 & 1 \\ 1 & 0 \end{bmatrix}$, then $A^2$ is equal to (A) $\begin{bmatrix} 0 & 1 \\ 1 & 0 \end{bmatrix}$ (B) $\begin…Preview
- Q57If matrix $A = [a_{ij}]_{2 \times 2}$, where $a_{ij} = 1$ if $i \neq j$ and $a_{ij} = 0$ if $i = j$, then $A^2$ is equal to (A) $I$ (B) $A$…Preview
- Q58The matrix $\begin{bmatrix} 1 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 4 \end{bmatrix}$ is a (A) identity matrix (B) symmetric matrix (C) skew symmet…Preview
- Q59The matrix $\begin{bmatrix} 0 & -5 & 8 \\ 5 & 0 & 12 \\ -8 & -12 & 0 \end{bmatrix}$ is a (A) diagonal matrix (B) symmetric matrix (C) skew s…Preview
- Q60If $A$ is matrix of order $m \times n$ and $B$ is a matrix such that $AB'$ and $B'A$ are both defined, then order of matrix $B$ is (A) $m \t…Preview
- Q61If $A$ and $B$ are matrices of same order, then $(AB' - BA')$ is a (A) skew symmetric matrix (B) null matrix (C) symmetric matrix (D) unit m…Preview
- Q62If $A$ is a square matrix such that $A^2 = I$, then $(A-I)^3 + (A+I)^3 - 7A$ is equal to (A) $A$ (B) $I - A$ (C) $I + A$ (D) $3A$Preview
- Q63For any two matrices $A$ and $B$, we have (A) $AB = BA$ (B) $AB \neq BA$ (C) $AB = O$ (D) None of the abovePreview
- Q64_________ matrix is both symmetric and skew symmetric matrix.Preview
- Q65Sum of two skew symmetric matrices is always _________ matrix.Preview
- Q66The negative of a matrix is obtained by multiplying it by _________.Preview
- Q67The product of any matrix by the scalar _________ is the null matrix.Preview
- Q68A matrix which is not a square matrix is called a _________ matrix.Preview
- Q69Matrix multiplication is _________ over addition.Preview
- Q70If $A$ is a symmetric matrix, then $A^3$ is a _________ matrix.Preview
- Q71If $A$ is a skew symmetric matrix, then $A^2$ is a _________.Preview
- Q72If $A$ and $B$ are square matrices of the same order, then (i) $(AB)' = $ _________. (ii) $(kA)' = $ _________. ($k$ is any scalar) (iii) $[…Preview
- Q73If $A$ is skew symmetric, then $kA$ is a _________. ($k$ is any scalar)Preview
- Q74If $A$ and $B$ are symmetric matrices, then (i) $AB - BA$ is a _________. (ii) $BA - 2AB$ is a _________.Preview
- Q75If $A$ is symmetric matrix, then $B'AB$ is _________.Preview
- Q76If $A$ and $B$ are symmetric matrices of same order, then $AB$ is symmetric if and only if _________.Preview
- Q77A matrix denotes a number.Preview
- Q78Matrices of any order can be added.Preview
- Q79Two matrices are equal if they have same number of rows and same number of columns.Preview
- Q80Matrices of different order can not be subtracted.Preview
- Q81Matrix addition is associative as well as commutative.Preview
- Q82Matrix multiplication is commutative.Preview
- Q83A square matrix where every element is unity is called an identity matrix.Preview
- Q84If $A$ and $B$ are two square matrices of the same order, then $A + B = B + A$.Preview
- Q85If $A$ and $B$ are two matrices of the same order, then $A - B = B - A$.Preview
- Q86If matrix $AB = O$, then $A = O$ or $B = O$ or both $A$ and $B$ are null matrices.Preview
- Q87Transpose of a column matrix is a column matrix.Preview
- Q88If $A$ and $B$ are two square matrices of the same order, then $AB = BA$.Preview
- Q89If each of the three matrices of the same order are symmetric, then their sum is a symmetric matrix.Preview
- Q90If $A$ and $B$ are any two matrices of the same order, then $(AB)' = A'B'$.Preview
- Q91If $(AB)' = B'A'$, where $A$ and $B$ are not square matrices, then number of rows in $A$ is equal to number of columns in $B$ and number of…Preview
- Q92If $A$, $B$ and $C$ are square matrices of same order, then $AB = AC$ always implies that $B = C$.Preview
- Q93$AA'$ is always a symmetric matrix for any matrix $A$.Preview
- Q94If $A = \begin{bmatrix} 2 & 3 & -1 \\ 1 & 4 & 2 \end{bmatrix}$ and $B = \begin{bmatrix} 2 & 3 \\ 4 & 5 \\ 2 & 1 \end{bmatrix}$, then $AB$ an…Preview
- Q95If $A$ is skew symmetric matrix, then $A^2$ is a symmetric matrix.Preview
- Q96$(AB)^{-1} = A^{-1} \cdot B^{-1}$, where $A$ and $B$ are invertible matrices satisfying commutative property with respect to multiplication.Preview
Sample & Board Papers
Sample papers and previous-year board questions for this subject.
+−Show 5 questionsHide questions5 questions
- Q1If for three matrices 𝐴 = [𝑎𝑖𝑗]𝑚×4 , B = [𝑏𝑖𝑗]𝑛×3 𝑎𝑛𝑑 C = [𝑐𝑖𝑗]𝑝×𝑞 products 𝐴𝐵 and 𝐴𝐶 both are defined and are square matrices of same order…Preview
- Q2The inverse of the matrix $\begin{bmatrix} 3 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 5 \end{bmatrix}$ is (A) $\begin{bmatrix} 0 & 0 & 3 \\ 0 & 2 & 0…Preview
- Q3Assume $X$, $Y$, $Z$, $W$ and $P$ are matrices of order $2\times n$, $3\times k$, $2\times p$, $n\times 3$ and $p\times k$, respectively. Th…Preview
- Q4If the matrix $A = \begin{pmatrix} 0 & a & -3 \\ 2 & 0 & -1 \\ b & 1 & 0 \end{pmatrix}$ is skew symmetric, find the values of '$a$' and '$b$…Preview
- Q5Given $A = \begin{bmatrix} 2 & -3 \\ -4 & 7 \end{bmatrix}$, compute $A^{-1}$ and show that $2A^{-1} = 9I - A$.Preview