Solution 2 to problem l2o57


Expressions | Parameters | Relevance | Back to problem l2o57

Expressions

The solution is given through the following expressions:

b45=0


      6      2
     ----*a14 *b12
      25
b44=---------------
            2
         a10


b43=0


b42=0


b41=0


      6
     ---*a14*b12
      5
b40=-------------
         a10


      4
     ---*a14*b12
      5
b39=-------------
         a10


      4
     ---*a14*b12
      5
b38=-------------
         a10


      2
     ---*a14*b12
      5
b37=-------------
         a10


          1      4
      - -----*a14 *b12
         125
b36=-------------------
            3
         a10 *a17


b35=0


      3      3
     ----*a14 *b12
      25
b34=---------------
          2
       a10 *a17


      6      3
     ----*a14 *b12
      25
b33=---------------
          2
       a10 *a17


         1      3
      - ----*a14 *b12
         50
b32=------------------
            2
         a10 *a17


      1      3
     ----*a14 *b12
      25
b31=---------------
          2
       a10 *a17


b30=0


b29=0


      2     2
     ---*a14 *b12
      5
b28=--------------
       a10*a17


      4     2
     ---*a14 *b12
      5
b27=--------------
       a10*a17


        2
     a14 *b12
b26=----------
     a10*a17


      3     2
     ---*a14 *b12
      5
b25=--------------
       a10*a17


      1      2
     ----*a14 *b12
      10
b24=---------------
        a10*a17


b23=0


      2
     ---*a14*b12
      7
b22=-------------
         a17


      12
     ----*a17*b12
      5
b21=--------------
         a10


         6      2
      - ----*a14 *b12
         25
b20=------------------
              2
           a10


         6      2
      - ----*a14 *b12
         25
b19=------------------
              2
           a10


      2
     ---*a14*b12
      5
b18=-------------
         a10


         6
      - ---*a14*b12
         5
b17=----------------
          a10


      4
     ---*a14*b12
      5
b16=-------------
         a10


         2
      - ---*a14*b12
         5
b15=----------------
          a10


b14=0


         1
      - ---*a14*b12
         5
b13=----------------
          a10


b11= - b12


b10= - 4*b12


     1      4
    ----*a14 *b12
     25
b9=---------------
         3
      a10 *a17


     1      3
    ----*a14 *b12
     10
b8=---------------
         2
      a10 *a17


     2     3
    ---*a14 *b12
     5
b7=--------------
         2
      a10 *a17


     1      3
    ----*a14 *b12
     10
b6=---------------
         2
      a10 *a17


     1     2
    ---*a14 *b12
     2
b5=--------------
      a10*a17


     3      2
    ----*a14 *b12
     10
b4=---------------
       a10*a17


     1      2
    ----*a14 *b12
     10
b3=---------------
       a10*a17


     1
    ----*a14*b12
     28
b2=--------------
        a17


a18=0


      1      2
     ----*a14
      10
a16=-----------
        a10


a15=0


a13=a14


     1
a12=---*a14
     2


a11=0


a9=2*a17


a8=a17


    5*a10*a17
a7=-----------
       a14


    5*a10*a17
a6=-----------
       a14


        3      2
     - ----*a14
        10
a5=--------------
        a10


a4= - a14


       1
a3= - ---*a14
       2


       1
a2= - ---*a10
       4


Parameters

Apart from the condition that they must not vanish to give a non-trivial solution and a non-singular solution with non-vanishing denominators, the following parameters are free:
 b12,a17,a14,a10

Relevance for the application:

The solution given above tells us that the system {u_s, v_s} is a higher order symmetry for the lower order system {u_t,v_t} where u=u(t,x) is a scalar function, v=v(t,x) is a vector function of arbitrary dimension and f(..,..) is the scalar product between two such vectors:
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

             1         2        1             2                   2
df(u,t)=( - ---*u  *a10 *a14 - ---*u  *a10*a14 *u - u  *u *a10*a14
             4   5x             2   3x               2x  x

                                     3         3  2                  2
          + u *f(v,v)*a10*a14*a17 - ----*u *a14 *u  + 5*f(v ,v  )*a10 *a17
             x                       10   x                x  2x

                          2
          + 5*f(v,v  )*a10 *a17 + 2*f(v,v )*a10*a14*a17*u)/(a10*a14)
                   3x                    x

          1          3            1          2    2
df(u,s)=(----*u  *a10 *a14*b12 + ----*u  *a10 *a14 *b12*u
          28   7x                 10   5x

             3             2    2        1             2    2
          + ----*u  *u *a10 *a14 *b12 + ---*u  *u  *a10 *a14 *b12
             10   4x  x                  2   3x  2x

             1                2                1              3      2
          - ---*u  *f(v,v)*a10 *a14*a17*b12 + ----*u  *a10*a14 *b12*u
             5   3x                            10   3x

             2                3          1     3        3
          + ---*u  *u *a10*a14 *b12*u + ----*u  *a10*a14 *b12
             5   2x  x                   10   x

             2                 2                4                 2
          - ---*u *f(v ,v )*a10 *a14*a17*b12 + ---*u *f(v,v  )*a10 *a14*a17*b12
             5   x    x  x                      5   x      2x

             6                    2              1         4      3
          - ----*u *f(v,v)*a10*a14 *a17*b12*u + ----*u *a14 *b12*u
             25   x                              25   x

                            3                        3
          - 4*f(v  ,v  )*a10 *a17*b12 - f(v ,v  )*a10 *a17*b12
                 2x  3x                    x  4x

             6               2                             3
          - ---*f(v ,v  )*a10 *a14*a17*b12*u + f(v,v  )*a10 *a17*b12
             5     x  2x                            5x

             2              2                  12                    2    2
          + ---*f(v,v  )*a10 *a14*a17*b12*u + ----*f(v,v )*f(v,v)*a10 *a17 *b12
             5       3x                        5        x

             6                  2          2      3
          - ----*f(v,v )*a10*a14 *a17*b12*u )/(a10 *a17)
             25       x

          1                                           2
df(v,t)=(---*u  *v *a10*a14 + u *v  *a10*a14 + v  *a10  + v  *a10*a14*u
          2   2x  x            x  2x            5x         3x

                                 1         2  2
          + v *f(v,v)*a10*a17 + ----*v *a14 *u )/a10
             x                   10   x

          1             2    2        3             2    2
df(v,s)=(----*u  *v *a10 *a14 *b12 + ---*u  *v  *a10 *a14 *b12
          10   4x  x                  5   3x  2x

                       2    2        1                 3
          + u  *v  *a10 *a14 *b12 + ----*u  *v *a10*a14 *b12*u
             2x  3x                  25   2x  x

             1     2           3        4            2    2
          - ----*u  *v *a10*a14 *b12 + ---*u *v  *a10 *a14 *b12
             50   x   x                 5   x  4x

             6                 3          2         3
          + ----*u *v  *a10*a14 *b12*u + ---*v  *a10 *a14*b12
             25   x  2x                   7   7x

             2         2    2          2                2
          + ---*v  *a10 *a14 *b12*u + ---*v  *f(v,v)*a10 *a14*a17*b12
             5   5x                    5   3x

             3              3      2    4                 2
          + ----*v  *a10*a14 *b12*u  + ---*v  *f(v,v )*a10 *a14*a17*b12
             25   3x                    5   2x      x

             4                 2                6                 2
          + ---*v *f(v ,v )*a10 *a14*a17*b12 + ---*v *f(v,v  )*a10 *a14*a17*b12
             5   x    x  x                      5   x      2x

             6                    2               1         4      3      3
          + ----*v *f(v,v)*a10*a14 *a17*b12*u - -----*v *a14 *b12*u )/(a10 *a17)
             25   x                              125   x

df(u,t)=( - 1/4*df(u,x,5)*a10**2*a14 - 1/2*df(u,x,3)*a10*a14**2*u - df(u,x,2)*df
(u,x)*a10*a14**2 + df(u,x)*f(v,v)*a10*a14*a17 - 3/10*df(u,x)*a14**3*u**2 + 5*f(
df(v,x),df(v,x,2))*a10**2*a17 + 5*f(v,df(v,x,3))*a10**2*a17 + 2*f(v,df(v,x))*a10
*a14*a17*u)/(a10*a14)$

df(u,s)=(1/28*df(u,x,7)*a10**3*a14*b12 + 1/10*df(u,x,5)*a10**2*a14**2*b12*u + 3/
10*df(u,x,4)*df(u,x)*a10**2*a14**2*b12 + 1/2*df(u,x,3)*df(u,x,2)*a10**2*a14**2*
b12 - 1/5*df(u,x,3)*f(v,v)*a10**2*a14*a17*b12 + 1/10*df(u,x,3)*a10*a14**3*b12*u
**2 + 2/5*df(u,x,2)*df(u,x)*a10*a14**3*b12*u + 1/10*df(u,x)**3*a10*a14**3*b12 - 
2/5*df(u,x)*f(df(v,x),df(v,x))*a10**2*a14*a17*b12 + 4/5*df(u,x)*f(v,df(v,x,2))*
a10**2*a14*a17*b12 - 6/25*df(u,x)*f(v,v)*a10*a14**2*a17*b12*u + 1/25*df(u,x)*a14
**4*b12*u**3 - 4*f(df(v,x,2),df(v,x,3))*a10**3*a17*b12 - f(df(v,x),df(v,x,4))*
a10**3*a17*b12 - 6/5*f(df(v,x),df(v,x,2))*a10**2*a14*a17*b12*u + f(v,df(v,x,5))*
a10**3*a17*b12 + 2/5*f(v,df(v,x,3))*a10**2*a14*a17*b12*u + 12/5*f(v,df(v,x))*f(v
,v)*a10**2*a17**2*b12 - 6/25*f(v,df(v,x))*a10*a14**2*a17*b12*u**2)/(a10**3*a17)$

df(v,t)=(1/2*df(u,x,2)*df(v,x)*a10*a14 + df(u,x)*df(v,x,2)*a10*a14 + df(v,x,5)*
a10**2 + df(v,x,3)*a10*a14*u + df(v,x)*f(v,v)*a10*a17 + 1/10*df(v,x)*a14**2*u**2
)/a10$

df(v,s)=(1/10*df(u,x,4)*df(v,x)*a10**2*a14**2*b12 + 3/5*df(u,x,3)*df(v,x,2)*a10
**2*a14**2*b12 + df(u,x,2)*df(v,x,3)*a10**2*a14**2*b12 + 1/25*df(u,x,2)*df(v,x)*
a10*a14**3*b12*u - 1/50*df(u,x)**2*df(v,x)*a10*a14**3*b12 + 4/5*df(u,x)*df(v,x,4
)*a10**2*a14**2*b12 + 6/25*df(u,x)*df(v,x,2)*a10*a14**3*b12*u + 2/7*df(v,x,7)*
a10**3*a14*b12 + 2/5*df(v,x,5)*a10**2*a14**2*b12*u + 2/5*df(v,x,3)*f(v,v)*a10**2
*a14*a17*b12 + 3/25*df(v,x,3)*a10*a14**3*b12*u**2 + 4/5*df(v,x,2)*f(v,df(v,x))*
a10**2*a14*a17*b12 + 4/5*df(v,x)*f(df(v,x),df(v,x))*a10**2*a14*a17*b12 + 6/5*df(
v,x)*f(v,df(v,x,2))*a10**2*a14*a17*b12 + 6/25*df(v,x)*f(v,v)*a10*a14**2*a17*b12*
u - 1/125*df(v,x)*a14**4*b12*u**3)/(a10**3*a17)$