Diagonalize Matrix Calculator (2×2)

The Diagonalize Matrix Calculator finds the eigenvalues of a 2×2 matrix, the diagonal matrix D, and whether the matrix is diagonalizable. Enter the four entries.

Formula

A = P·D·P⁻¹ where D holds the eigenvalues on its diagonal
  • A 2×2 matrix is diagonalizable if it has two distinct eigenvalues, or is already diagonal.
  • A repeated eigenvalue with only one independent eigenvector is not diagonalizable.

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

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

Eigenvalues 3 and 1, so D = [[3,0],[0,1]] and the matrix is diagonalizable.

Frequently asked questions

When is a matrix diagonalizable?
When it has enough independent eigenvectors — for 2×2, when the two eigenvalues are distinct or it is already diagonal.