Eigenvalue and Eigenvector Calculator (2×2)

The Eigenvalue and Eigenvector Calculator finds the eigenvalues and eigenvectors of a 2×2 matrix by solving its characteristic equation. Enter the four matrix entries.

Formula

Solve det(A − λI) = 0: λ = (trace ± √(trace² − 4·det)) / 2
  • Eigenvectors solve (A − λI)v = 0 for each eigenvalue.
  • A negative discriminant gives complex-conjugate eigenvalues.

[[2,1],[1,2]]

Inputs
  • a₁₁: 2
  • a₁₂: 1
  • a₂₁: 1
  • a₂₂: 2

λ = 3 and 1, with eigenvectors (1, 1) and (1, −1).

Frequently asked questions

What is an eigenvector?
A non-zero vector whose direction is unchanged by the matrix; it is only scaled by its eigenvalue.