
then
A
T
5
26
231
53
2
4
3
5
Remarks:
i. A is symmetric3A
T
5 A
ii. A is skew-symmetric3A
T
52A
3.4 Properties of Matrix Operations
Let A, B, and C be given matrices, then the basic properties of matrix addition, sca-
lar multiplication, matrix multiplication, and matrix transposition are stated below
without proof. These properties can be easi ly verified in examples.
1. Properties of matrix addition and scalar multiplication:
i. A 1 B 5 B 1 A (commutativity)
ii. ðA 1 BÞ1 C 5 A 1 ðB 1 CÞ (associativity)
iii. A 1 O 5 O 1 A 5 A, where O is the corresponding null matrix
iv. kðA 1 BÞ5 kA 1 kB, where k is a scalar (distributivity).
2. Properties of matrix multiplication