I was going to demonstrate the action of Maple for a symmetric 3 by 3 real matrix with 1, 2, and 3 distinct eigenvalues and got strange results. It may be that I need to explicitly tell Maple that the matrix is symmetric and real. (How would I do this?)

For example, after with(LinearAlgebra) I put tmat1:=Matrix(3,3,[1,2,3,2,4,5,3,5,6]), and get eigenvalues with small imaginary parts (!). When I put tmat2:=Matrix(3,3,[0,1,1,1,0,1,1,1,0...