In each of the following cases, let T be the linear operator on R2 which is represented by the matrix A in the standard ordered basis for R2, and let U be the linear operator on C2 represented by A in the standard ordered basis. Find the characteristic polynomial for T and that for U, find the characteristic values of each operator, and for each such characteristic value c find a basis for the corresponding space of characteristic vectors.
A=[1000],A=[2−131],A=[1111].