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

> K:=40*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 := 40 [                    ]
                            [ 0    -8    16    -8]
                            [                    ]
                            [ 0     1    -8     7]

> M:=matrix(4,4,[16,2,0,0,  2,8,2,-1,  0,2,16,2,  0,-1,2,4]);  

                          [16     2     0     0]
                          [                    ]
                          [ 2     8     2    -1]
                     M := [                    ]
                          [ 0     2    16     2]
                          [                    ]
                          [ 0    -1     2     4]

> det(K-Omega*M);

                                                 2                3
  5898240000 - 2752512000 Omega + 152166400 Omega  - 2048000 Omega

                     4
         + 6800 Omega

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

          2.468664756, 22.94616601, 77.06313717, 198.6985027

> map(sqrt, [%]);
> 
> 

         [1.571198509, 4.790215654, 8.778561224, 14.09604564]

> 
