Rationalised 2023-24
 40
MATHEMATICS
(iv)
Diagonal matrix
A square matrix B = [bij] m × m is said to be a diagonal matrix if all its non
diagonal elements are zero, that is a matrix B = [bij] m × m is said to be a diagonal
matrix if bij = 0, when i ≠ j For example,  A = [4], 
1
0
B
0
2
−

= 



, 
1 1
0
0
C
0
2
0
0
0
3
−



= 





, are diagonal matrices
of order 1, 2, 3, respectively (v)
Scalar matrix
A diagonal matrix is said to be a scalar matrix if its diagonal elements are equal,
that is, a square matrix B = [bij] n × n is said to be a scalar matrix if
bij = 0,    when i  ≠ j
bij = k,    when i  = j, for some constant k