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P6 Topic 2: Matrix algebra
Eigenvalues of 2 x 2 matrices backmore
The eigenvalues of the matrix A
2x2 matrix
are the solutions to the equation: det(A-lI) = 0
This simplifies to a quadratic equation which is called the characteristic equation:
l²-(a+d)l +ad-bc = 0

Matrix A:
Eigenvalues

Summary
The roots of the charactieristic equation are the eigenvalues, but are also known as characteristic roots or latent roots.
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