What is the determinant of the following Householder matrix I−2 hat(x) hat(x)x^^^TT where hat(x) is a normalized vector, i.e., norm(hat(x))=1?

Layton Park

Layton Park

Answered question

2022-11-17

What is the determinant of the following Householder matrix
I 2 x ^ x ^
where x ^ is a normalized vector, i.e., x ^ = 1?
This is always −1 somehow but can't find proof of it anywhere.

Answer & Explanation

Samsonitew7b

Samsonitew7b

Beginner2022-11-18Added 15 answers

The eigenvalues of the matrix x ^ x ^ T are ( n 1 ) zeros and one eigenvalue of 1. Therefore, the eigenvalues of ( I 2 x ^ x ^ T ) are ( n 1 ) 1 s and one eigenvalue of (−1). Since the determinant is equal to the product of the eigenvalues, then the determinant will be (−1).

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?