> with(linalg):
Warning, the protected names norm and trace have been redefined and
unprotected

> K:=16/3*matrix(4,4,[16,-8,0,0,  -8,14,-8,1,  0,-8,16,-8,  0,1,-8,7]); 

                             [16    -8     0     0]
                             [                    ]
                             [-8    14    -8     1]
                   K := 16/3 [                    ]
                             [ 0    -8    16    -8]
                             [                    ]
                             [ 0     1    -8     7]

> M:=matrix(4,4,[2,0,0,0,  0,2,0,0,  0,0,2,0,  0,0,0,1]);  

                            [2    0    0    0]
                            [                ]
                            [0    2    0    0]
                       M := [                ]
                            [0    0    2    0]
                            [                ]
                            [0    0    0    1]

> det(K-Omega*M);

                                               2             3
  16777216/9 - 8126464/9 Omega + 558080/9 Omega  - 1280 Omega

                  4
         + 8 Omega

> fsolve(det(K-Omega*M)=0,Omega);

          2.459020908, 21.16382992, 55.06493391, 81.31221526

> map(sqrt, [%]);
> 

         [1.568126560, 4.600416277, 7.420575039, 9.017328610]

> 
