Find all possible real values λ such that det(A − λI3) = 0. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) A = −5 −4 −9 0 0 2 0 0 8

Respuesta :

Answer:

λ = 8,-5,0

Step-by-step explanation:

given matrix,

A = [tex]\left[\begin{array}{ccc}-5&-4&-9\\0&0&2\\0&0&8\end{array}\right][/tex]

det (A − λI) = 0

A − λI = 0

[tex]\left[\begin{array}{ccc}-5&-4&-9\\0&0&2\\0&0&8\end{array}\right][/tex]-λ [tex]\left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right][/tex]=0

[tex]\left[\begin{array}{ccc}-5-\lambda&-4&-9\\0&-\lambda&2\\0&0&8-\lambda\end{array}\right][/tex]=0

now finding determinant

( 8-λ){ (-5-λ)(-λ)- 0} = 0

λ = 8,-5,0

The possible values of λ are -5, 0, and 8.

Given

A matrix A, the eigenvalues of A, called  are scalars who comply with the relation:

Eigenvalues of a Matrix

There is a vector such that for some scalar, then is called the eigenvalue of with corresponding (right) eigenvector,

det (A − λI) = 0

Where I refer to the identity matrix.

The identity matrix is;

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

Then,

The value of λ is;

[tex]\rm A-\lambda I= 0\\\\\left[\begin{array}{ccc}-5&-4&-9\\0&0&2\\0&0&8\end{array}\right] - \lambda\rm \left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right]=0\\\\\left[\begin{array}{ccc}-5&-4&-9\\0&0&2\\0&0&8\end{array}\right] -\rm \left[\begin{array}{ccc}\lambda &0&0\\0&\lambda &0\\0&0&\lambda \end{array}\right]=0\\\\ -5-\lambda =0 , \ \lambda =-5\\\\8-\lambda =0, \ \lambda =8\\\\0-\lambda =0, \ \lambda =0[/tex]

Hence, the possible values of λ are -5, 0, and 8.

To know more about the matrix click the link given below.

https://brainly.com/question/4470545