How Can I Determine The Minimal Polynomial Of A Matrix A With Distinct Eigenvalues Λ1 And Λ2, But With A Non-trivial Jordan Block Structure, Specifically When A Is A 6x6 Matrix And The Jordan Block Corresponding To Λ1 Is 3x3 And The Jordan Block Corresponding To Λ2 Is 3x3 As Well?

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To determine the minimal polynomial of a matrix A{ A } which is a 6x6 matrix with distinct eigenvalues λ1{ \lambda_1 } and λ2{ \lambda_2 }, each having a 3x3 Jordan block, we need to consider the structure of the Jordan blocks.

  1. Eigenvalues and Jordan Blocks: The matrix A{ A } has two distinct eigenvalues λ1{ \lambda_1 } and λ2{ \lambda_2 }, each with a single 3x3 Jordan block. This means the largest Jordan block for each eigenvalue is 3x3.

  2. Minimal Polynomial Factors: For each eigenvalue, the minimal polynomial will have a factor of (xλ)3{ (x - \lambda)^3 } because the largest Jordan block size is 3.

  3. Combining Factors: Since λ1{ \lambda_1 } and λ2{ \lambda_2 } are distinct, the minimal polynomial is the product of the minimal polynomials for each eigenvalue. Therefore, the minimal polynomial will be the product of (xλ1)3{ (x - \lambda_1)^3 } and (xλ2)3{ (x - \lambda_2)^3 }.

  4. Conclusion: The minimal polynomial of matrix A{ A } is the product of these factors, which is (xλ1)3(xλ2)3{ (x - \lambda_1)^3 (x - \lambda_2)^3 }.

Thus, the minimal polynomial of matrix A{ A } is (xλ1)3(xλ2)3{\boxed{(x - \lambda_1)^3 (x - \lambda_2)^3}}.