How to Calculate Characteristic Polynomial

The characteristic polynomial of a matrix A is given by:

det(A - λI) = 0

Where:

• A is the original matrix
• λ is the eigenvalue
• I is the identity matrix

For a 2×2 matrix:

• Original matrix: [[a, b], [c, d]]
• Characteristic polynomial: λ² - (a+d)λ + (ad-bc)