Let be an n times n matrix Which of the following is false I
     Let be an n times n matrix. Which of the following is false?  If is an eigenvalue, Ax = lambda x for some nonzero vector x.  Row reducing A into echelon form is usually not an effective way of finding eigenvalues.  If 0 is an eigenvalue of a matrix A, A is not invertible.  If two eigenvectors are linearly independent, they correspond to distinct eigenvalues. 
  
  Solution
a) , c) ,d) are are correct and can be proved
b ) is False as It is known that if a matrix is given in upper triangular form, then we can just read off the eigenvalues (and their algebraic multiplicity) on the main diagonal of the matrix.
So, Option b is False

