Diagonalization of a given matrix

Let A=[211101110].

  1. Compute the characteristic polynomial pA(x) of A. It has integer roots.
  2. For each eigenvalue λ of A, find a basis for the eigenspace Eλ.
  3. Determine if A is diagonalizable. If so, give matrices P and B such that P1AP=B and B is diagonal. If no, explain carefully why A is not diagonalizable.