DefinitionAn Eigenvalue is a scalar value that represents a scaling factor in the linear equations represented by matrices. Given a matrix A, an eigenvalue λ and its corresponding eigenvector v are defined by Av = λv. Eigenvalues describe how a matrix stretches, compresses or rotates vectors in the direction of its eigenvectors. Eigenvalues determine the stability, or otherwise, of systems in linear algebra, differential equations and physics - they provide information concerning the dynamics of a system and its equilibrium points. For Example EIGENVALUES OF A 2x2 MATRIX. the eigenvalues of a 2x2 matrix [acbd], are the solutions to the characteristic equation λ2−(a+d)λ+(ad−bc)=0.