Math Problem Statement

Diagonalize the matrix A = [[2, 2, 0], [2, 1, 1], [- 7, 2, - 3]] find eigen vectors

Solution

To diagonalize a matrix AA, we need to:

  1. Find the eigenvalues of AA by solving the characteristic equation det(AλI)=0\det(A - \lambda I) = 0, where λ\lambda is the eigenvalue and II is the identity matrix.
  2. Find the corresponding eigenvectors for each eigenvalue.

The matrix AA is given as:

A=(220211723)A = \begin{pmatrix} 2 & 2 & 0 \\ 2 & 1 & 1 \\ -7 & 2 & -3 \end{pmatrix}

Step 1: Find Eigenvalues

The characteristic equation is det(AλI)=0\det(A - \lambda I) = 0, where II is the identity matrix.

Let's calculate this determinant first:

det((220211723)λ(100010001))=0\det \left( \begin{pmatrix} 2 & 2 & 0 \\ 2 & 1 & 1 \\ -7 & 2 & -3 \end{pmatrix} - \lambda \begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} \right) = 0

This results in:

det(2λ2021λ1723λ)=0\det \begin{pmatrix} 2 - \lambda & 2 & 0 \\ 2 & 1 - \lambda & 1 \\ -7 & 2 & -3 - \lambda \end{pmatrix} = 0

Now, let me calculate the determinant and find the eigenvalues.The eigenvalues of the matrix AA are:

λ1=4,λ2=3,λ3=1\lambda_1 = -4, \quad \lambda_2 = 3, \quad \lambda_3 = 1

The corresponding eigenvectors are:

v_2 = \begin{pmatrix} -0.6667 \\ -0.3333 \\ 0.6667 \end{pmatrix}, \quad v_3 = \begin{pmatrix} -0.4364 \\ 0.2182 \\ 0.8729 \end{pmatrix}$$ ### Conclusion: The matrix $$A$$ can be diagonalized as $$A = PDP^{-1}$$, where $$D$$ is the diagonal matrix with eigenvalues $$\lambda_1, \lambda_2, \lambda_3$$, and the columns of $$P$$ are the corresponding eigenvectors. Would you like more details on the diagonalization process or on any other step? ### Follow-up questions: 1. How do you calculate the determinant of a 3x3 matrix? 2. How can we verify if a given vector is an eigenvector of a matrix? 3. What are the steps for finding $$P^{-1}$$ once you have $$P$$? 4. Can the matrix $$A$$ have repeated eigenvalues, and what does that imply? 5. How does the matrix's diagonal form help in solving differential equations? **Tip:** Eigenvectors corresponding to distinct eigenvalues are linearly independent, which ensures the diagonalization of the matrix is possible.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Algebra
Eigenvalues
Eigenvectors
Matrix Diagonalization

Formulas

Characteristic Equation: det(A - λI) = 0
Eigenvector Equation: (A - λI)v = 0
Matrix Diagonalization: A = PDP^{-1}

Theorems

Eigenvalue Theorem
Diagonalization Theorem

Suitable Grade Level

Undergraduate Level (Linear Algebra)