Question

In the world of matrices if null matrix represents a zero ,then ______ represents a one.

• A. Singular matrix
• B. Identity matrix
• C. Nilpotent matrix
• D. Symmetric matrix

Answer 1

The correct option is B

Identity matrix

You can comfortably say that identity matrix corresponds to one in matrix world. The rationale behind this is that if you multiply any matrix A with identity matrix, then you get A itself just like the case of 1 multiplied by a number gives the same number.

Identity matrix is given by a square matrix with all the diagonal elements as one and non diagonal elements as zeroes.

A 3 $\times$ 3 identity matrix is given below.

$I=\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right]$