CHAPTER 2: Matrices

Question 1

A set of mn numbers (real or complex), arranged in a rectangular formation (array or table) having m rows and n columns and enclosed by a square bracket [ ]

Answer 1

Matrix

Question 2

A matrix consisting of a single row

Answer 2

Row Matrix/Row Vector

Question 3

a matrix having single column

Answer 3

Column Matrix / Column Vector

Question 4

A matrix in which each element is ‘0’

Answer 4

Null or Zero Matrix

Question 5

Zero matrices are generally denoted
by the symbol ____

Answer 5

O

Question 6

A matrix A having same numbers of rows and columns

Answer 6

Square Matrix

Question 7

A matrix A of order m x n can be written as ______

Answer 7

Amxn.

Question 8

If m = n, then the matrix is said to be a ______

Answer 8

square matrix.

Question 9

A square matrix of order n x n, is simply written as _____

Answer 9

An.

Question 10

The ______ of a square matrix is the ordered set of elements aij, where i = j, extending
from the upper left-hand corner to the lower right-hand corner of the matrix.

Answer 10

principal diagonal

Question 11

A square matrix in which all elements are zero except
those in the main or principal diagonal

Answer 11

Diagonal Matrix

Question 12

In diagonal matrix, some elements of the principal
diagonal may be ________

Answer 12

zero but not all.

Question 13

A diagonal matrix in which all the diagonal elements are same

Answer 13

Scalar Matrix

Question 14

A scalar matrix in which each diagonal element is
1(unity)

Answer 14

Identity Matrix or Unit Matrix

Question 15

An identity matrix of order n is denoted by _____.

Answer 15

In

Question 16

If a matrix A and identity matrix I are comformable for multiplication, then I has the property ______

Answer 16

AI=IA=A

Question 17

Two matrices A and B are said to be equal if and only if they have the ______ and each element of matrix A is equal to the corresponding element of matrix B

Answer 17

same order

Question 18

The negative of the matrix Amxn, denoted by _____, is the matrix formed by replacing each element in the matrix Amxn with its ________

Answer 18

–Amxn; additive inverse.

Question 19

If A is a matrix and k is a _______, then ____ is a matrix whose elements are the elements of A, each multiplied by k

Answer 19

scalar (constant); kA

Question 20

If A and B are two matrices of _______ m n then their sum A + B is defined as C, m n matrix such that each element of C is the sum of the corresponding elements of A and B.

Answer 20

same order

Question 21

Two matrices A and B are said to be _____ for the product AB if the number of columns of A is
equal to the number of rows of B.

Answer 21

conformable

Question 22

Multiplication of matrices is not _____

Answer 22

commutative

Question 23

A matrix A can be multiplied by itself if and only if it is a _______

Answer 23

square matrix