NDA 2025
- Exam
- NDA
- Year
- 2025
- Subject
- Mathematics
- Chapter
- Matrices
NDA 2025 · Mathematics · Matrices
If A = pmatrix x & y & z y & z & x z & x & y pmatrix where x , y ,...
If where , , are integers, is an orthogonal matrix, then what is equal to?
Options
- ANull matrix
- BIdentity matrix
- C
- D
Correct answer
B. Identity matrix
Step-by-step solution
Given the matrix .
The transpose of is given by:
We can observe that , which means is a symmetric matrix.
It is given that is an orthogonal matrix. By the definition of an orthogonal matrix, we have:
Substituting into the above equation, we get:
Thus, is equal to the identity matrix.
Answer: Identity matrix
The transpose of is given by:
We can observe that , which means is a symmetric matrix.
It is given that is an orthogonal matrix. By the definition of an orthogonal matrix, we have:
Substituting into the above equation, we get:
Thus, is equal to the identity matrix.
Answer: Identity matrix