f(λ)=（λ-1)(λ-1)(λ+1) So λ=1 or -1 When λ=1: Compute the equation system [E-A]X=O; we get X=(-1,-2,1)' so the eigenvector belonging to λ=1 is ζ1=-ε1-2ε2+ε3 When λ=-1 Compute the equation system [-E-A]X=O we get X=(1,1,1)' So the eigenvector belonging to λ=-1 is ζ2=ε1-ε2+ε3
