- Zero Matrix / Null Matrix
A matrix with all its entries as zero is said to be a null matrix. Note that a null matrix
can be of any order.
Eg : A = ⎟⎟
⎠
⎞
⎜⎜⎝
⎛
0 0 0
0 0 0
Here the matrix A has all its entries as zero, and also has two rows and three columns
and hence A is a zero matrix of order 2×3.
As the child is already familiar with all the basic ideas of a matrix, the idea of a zero
matrix can be taught to him/her orally supported by relevant text material in Braille.
- Diagonal matrix
A square matrix with all its entries zero, except those along the leading diagonal is
said to be a diagonal matrix. Note that only a square matrix can be diagonal matrix.
Eg. : A = ⎟⎟
⎠
⎞
⎜⎜⎝
⎛
0 − 7
2 0
Here, the matrix A is a square matrix of order 2, and the matrix has all its entries zero,
except those along the leading diagonal.
- Scalar Matrix
A diagonal matrix in which all the diagonal elements are same is said to be a scalar
matrix. Note that, a scalar matrix is basically a square matrix.
Eg : C = ⎟⎟
⎟
⎠
⎞
⎜
⎜
⎜
⎝
⎛
0 0 4
0 4 0
4 0 0
Note that the above matrix C is a diagonal matrix in which all the diagonal elements are
same, and hence the matrix is a scalar matrix.
The concept of scalar matrix can also be taught to the child verbally supported by
relevant text material in Braille.
