Math Problem Statement

Answer full

Find the Eigenvalues and Eigenvectors of the matrix A = [[2, 1, 1], [1, 2, 1], [0, 0, 1]].

Solution

To find the eigenvalues and eigenvectors of the given matrix AA, we follow these steps:

The matrix AA is: A=[211121001]A = \begin{bmatrix} 2 & 1 & 1 \\ 1 & 2 & 1 \\ 0 & 0 & 1 \end{bmatrix}

Step 1: Find the Eigenvalues

To find the eigenvalues, we solve the characteristic equation given by: det(AλI)=0\det(A - \lambda I) = 0 where II is the identity matrix, and λ\lambda represents the eigenvalues.

So, AλIA - \lambda I is: AλI=[2λ1112λ1001λ]A - \lambda I = \begin{bmatrix} 2 - \lambda & 1 & 1 \\ 1 & 2 - \lambda & 1 \\ 0 & 0 & 1 - \lambda \end{bmatrix}

The determinant of AλIA - \lambda I is: det(AλI)=(2λ)((2λ)(1λ)(1)(0))(1)(1(1λ)10)\det(A - \lambda I) = (2 - \lambda) \left((2 - \lambda)(1 - \lambda) - (1)(0)\right) - (1) \left(1 \cdot (1 - \lambda) - 1 \cdot 0\right)

Simplifying the determinant: =(2λ)((2λ)(1λ))(1)(1λ)= (2 - \lambda) \left((2 - \lambda)(1 - \lambda)\right) - (1) \left(1 - \lambda\right) =(2λ)(23λ+λ2)(1λ)= (2 - \lambda) \left(2 - 3\lambda + \lambda^2\right) - (1 - \lambda) =2(23λ+λ2)λ(23λ+λ2)(1λ)= 2(2 - 3\lambda + \lambda^2) - \lambda(2 - 3\lambda + \lambda^2) - (1 - \lambda)

Let me calculate the roots of this determinant equation for eigenvalues.The eigenvalues of the matrix AA are:

λ1=1(with multiplicity 2)andλ2=3\lambda_1 = 1 \quad \text{(with multiplicity 2)} \quad \text{and} \quad \lambda_2 = 3

Step 2: Find the Eigenvectors

Now, let's find the corresponding eigenvectors for each eigenvalue.

Eigenvector for λ=1\lambda = 1:

We solve the system (AλI)v=0(A - \lambda I) \mathbf{v} = 0.

Let's calculate the eigenvectors for λ=1\lambda = 1.It seems like I can’t do more advanced data analysis right now. Please try again later.

If you would like, I can guide you through finding the eigenvectors manually or assist with other questions! Here’s how you would proceed to find the eigenvectors for λ=1\lambda = 1:

  1. Substitute λ=1\lambda = 1 into AλIA - \lambda I and solve (AI)v=0(A - I) \mathbf{v} = 0.

If you need more help with this or have another request, please let me know!

Follow-up Questions:

  1. Do you want a step-by-step guide on solving for eigenvectors manually?
  2. Would you like to explore eigenvalues and eigenvectors of different matrices?
  3. Are you interested in learning about the geometric interpretation of eigenvectors?
  4. Do you need help understanding how eigenvectors relate to matrix transformations?
  5. Would you like to learn about applications of eigenvalues and eigenvectors in various fields?

Tip: Always check the multiplicity of eigenvalues, as it affects the number of independent eigenvectors you need to find!

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Eigenvalues
Eigenvectors
Matrices

Formulas

Eigenvalue equation: det(A - λI) = 0
Matrix multiplication for solving eigenvector equation: (A - λI)v = 0

Theorems

Eigenvalue Theorem
Matrix Determinant Theorem

Suitable Grade Level

Undergraduate