1. is Identity Matrix ?
`[[1,0],[0,1]]`
Solution:
A square matrix, in which all diagonal elements are unity and all other elements are zero, is called an identity matrix or a unit matrix.
Or
A diagonal matrix, in which all diagonal elements are unity, is called an identity matrix or a unit matrix.
Here, all diagonal elements are unity and all other elements are zero, so it is an identity matrix or a unit matrix.
2. is Identity Matrix ?
`[[1,2],[0,3]]`
Solution:
A square matrix, in which all diagonal elements are unity and all other elements are zero, is called an identity matrix or a unit matrix.
Or
A diagonal matrix, in which all diagonal elements are unity, is called an identity matrix or a unit matrix.
Here, `a_(12)=2!=0`, so it is not an identity matrix.
This material is intended as a summary. Use your textbook for detail explanation.
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