試題詳解

34. Let ， which of the following statement is incorrect? 
(A) The rank of A is 3.
(B) The inverse matrix is
(C) If we define the characteristic polynomial of A is f(t)=det(A-tI_n), then f(1)=-t³+3t²+3t-1.
(D) One of the eigenvalues is -1 and the corresponding eigenvector is (-2, 1, 2)^T.
(E) The matrix cannot be diagonalized over the real field.