Linear Algebra

2×2 Eigenvalues

Eigenvalues of a 2×2 matrix.

Formula

Formula
λ = tr ± tr2−4det2

Variables

SymbolDefinitionType & rangeUnitsRole
A 2×2 matrix real matrix input
λ eigenvalues computed result result

Try it yourself

Interactive calculator
rows separated by ';' , values by commas
Result

Worked examples

Example 1
GivenA = 2, 1; 1, 2
Result
λ1
3
λ2
1
Example 2
GivenA = 4, 1; 2, 3
Result
λ1
5
λ2
2