Let $$A = \left[ {\matrix{ 3 & 0 & 3 \cr 0 & 3 & 0 \cr 3 & 0 & 3 \cr } } \right]$$. Then, the roots of the equation det $$(A - \lambda {I_3})$$ = 0 (where I₃ is the identity matrix of order 3) are

In a third order matrix A, a_ij denotes the element in the ith row and jth column. If a_ij = 0 for i = j

= 1 for i > j

= $$-$$ 1 for i < j

Then the matrix is