Unit matrix

Question

Define unit matrix and illustrte using examples

Answer 1

The "unit matrix" can also be referred to as the "identity matrix." In multiplication, the number "1" is called identity because when you multiply 1 by something (let's call it S), you get S.

 

In matrix multiplication, the same rule applies. When we multiply the matrix A by the identity matrix, we get the matrix A.

 

So, what is that matrix? If you create a matrix of nxn dimensions, put 1's along the diagonal and 0's everywhere else. Go ahead and try this:

 

[ 2  4      x    [1  0

  0  2]            0  1]

 

You get:

[2  4

 0  2]