Page 60 - DMTH201_Basic Mathematics-1

Unit 3: Matrix

Thus, the matrix Notes

Cars Jeeps
A = M 1 10 5
M 8 9
2
20 10
Further, 2A . This matrix gives the number of cars and Jeeps produced by each unit
16 18
of the company in two days.

3.4 Operation of Matrices

1. Addition of matrices: Addition of two matrices A and B is defined if and only if they are of
the same order.

Notes If A and B are not of same order, then A + B is not defined. e.g.
2 3 1 2 3
A , B , then A +B is not defined. We may observe that addition of
1 0 1 0 1
matrices is an example of binary operation or the set of matrices of same order.
If A and B are matrices of the same order then their sum A B is obtained by adding the
corresponding elements of A and B.

2 1 0 0 1 7
Example: A , B
4 7 10 5 8 15
2 3 2 3
2 0 1 ( 1) 0 7
then A B
4 5 7 8 10 15
2 3
2 2 7
9 15 25
2 3
0 2 ( 1) ( 1) 7 0
B A
5 4 8 7 15 10
2 3

2 2 7
9 15 25
2 3

A B B . A
2. Subtraction of matrices: Subtraction of two matrices A and B is defined if and only if they
are of the same order.
If A and B are matrices of the same order then their difference A B is obtained by
subtracting the elements of B by the corresponding elements of A.

LOVELY PROFESSIONAL UNIVERSITY 53