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let A be a square matrix such that A^2 -3A + 2I = 0. what can you conclude about the eigenvalues of A?

User Pykih
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A's eigenvalues are 1 and 2 (real, distinct), making it non-singular and potentially diagonalizable.

Eigenvalues of a Square Matrix Satisfying A^2 - 3A + 2I = 0

The given equation, A^2 - 3A + 2I = 0, represents the characteristic polynomial of the square matrix A. This polynomial determines the eigenvalues of A, which are the special values (λ) for which the equation Ax - λx = 0 has non-trivial solutions (x ≠ 0).

Here's how we can analyze the eigenvalues of A:

Factoring the characteristic polynomial: We can factor the given polynomial as (A - 1)(A - 2) = 0. This indicates that the eigenvalues of A are 1 and 2.

Properties of eigenvalues:

Real and distinct: Since the eigenvalues are 1 and 2, both real and distinct, A will have two corresponding eigenvectors that are linearly independent.

Trace and determinant: The sum of the eigenvalues (trace) is 1 + 2 = 3, and their product (determinant) is 1 * 2 = 2.

Geometric interpretation: Eigenvalues and eigenvectors can be visualized geometrically. In this case, the eigenvectors will define directions in the n-dimensional space where A operates, and the eigenvalues represent the scaling factors applied along those directions.

Implications for A:

Non-singular: Since both eigenvalues are non-zero, A is invertible and has a full rank.

Diagonalizability: If A has n linearly independent eigenvectors, it can be diagonalized by a similarity transformation, where the diagonal elements are the eigenvalues.

Therefore, the eigenvalues of A are 1 and 2, which are both real and distinct. This implies that A is non-singular and can be diagonalized under certain conditions.

User Anil Ugale
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