is an matrix.
Check the true statements below:
A.
Finding an eigenvector of might be difficult, but checking whether a given vector is in fact an eigenvector is easy.
B.
A number is an eigenvalue of if and only if the equation has a nontrivial solution .
C.
A matrix is not invertible if and only if 0 is an eigenvalue of .
D.
If for some vector , then is an eigenvalue of .
E.
To find the eigenvalues of , reduce to echelon form.