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

> L[1]:=xi -> xi;

                           L[1] := xi -> xi

> L[2]:=xi -> 1-xi;

                         L[2] := xi -> 1 - xi

> N[1]:=xi -> (1+2*L[1](xi))*L[2](xi)^2;

                                                      2
               N[1] := xi -> (1 + 2 L[1](xi)) L[2](xi)

> N[2]:=xi -> l*L[1](xi)*L[2](xi)^2;

                                                   2
                  N[2] := xi -> l L[1](xi) L[2](xi)

> N[3]:=xi -> L[1](xi)^2*(1+2*L[2](xi));

                                     2
               N[3] := xi -> L[1](xi)  (1 + 2 L[2](xi))

> N[4]:=xi -> -l*L[1](xi)^2*L[2](xi);

                                          2
                 N[4] := xi -> -l L[1](xi)  L[2](xi)

> Formfunktionen:=matrix(1,4,[N[1],N[2],N[3],N[4]]);

           Formfunktionen := [N[1]    N[2]    N[3]    N[4]]

> Nd:=map(collect,map(diff,Formfunktionen(xi),xi),xi):
> J:=multiply(transpose(Nd), Nd):
> p:=map(int,J,xi=0..1);

                   [          l                   l   ]
                   [6/5      ----      -6/5      ---- ]
                   [          10                  10  ]
                   [                                  ]
                   [            2                   2 ]
                   [ l       2 l         l         l  ]
                   [----     ----     - ----    - ----]
                   [ 10       15         10        30 ]
              p := [                                  ]
                   [           l                   l  ]
                   [-6/5    - ----     6/5      - ----]
                   [           10                  10 ]
                   [                                  ]
                   [            2                   2 ]
                   [ l         l         l       2 l  ]
                   [----    - ----    - ----     ---- ]
                   [ 10        30        10       15  ]

> K:=(E*A/(l*30))*evalm(30*p);

                           [36     3 l     -36     3 l ]
                           [                           ]
                           [          2              2 ]
                           [3 l    4 l     -3 l    -l  ]
                       E A [                           ]
                           [-36    -3 l     36     -3 l]
                           [                           ]
                           [         2                2]
                           [3 l    -l      -3 l    4 l ]
             K := 1/30 ---------------------------------
                                       l

> 
> 
> 
