Find the eigenvalues of the matrix [[3, 1], [1, 3]]

Published on December 1, 2024

Linear-Algebra

The eigenvalues of the matrix [[3, 1], [1, 3]] are 4 and 2.

Question

eigenvalues of [[3, 1], [1, 3]]

Answer

Here’s how to find the eigenvalues of the matrix :
  1. Find the characteristic equation. The characteristic equation is given by , where is the matrix, represents the eigenvalues, and is the identity matrix.
    In our case, and . So, .
  2. Calculate the determinant. The determinant of a 2x2 matrix is . Therefore, the determinant of is:
    .
  3. Solve the characteristic equation. We set the determinant equal to zero and solve for :
    This is a quadratic equation. We can factor it as:
  4. Find the eigenvalues. The solutions to the equation are and . These are the eigenvalues of the matrix.
Therefore, the eigenvalues of the matrix are 4 and 2.
Final Answer: The final answer is