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P. 59

dp   dp  dy   dp
                                            
                                             y               , p                                   (3.13)
                                               dx   dy  dx   dy

                                        y d   d  dp   d  2  p   dp  dp  dy  d  2  p  dp
                                                                                   2
                                     
                                  y          (   p)       pp                 p   (  )  2  p
                                       dx    dx  dy     dy 2      dy  dy  dx  dy 2     dy

                                 and etc It is visible from the conducted calculations, that  y (k )   is
                                 expressed through derivative functions р(у), the order of which
                                 does  not  exceed  k-1,  and  also  in.  As  a  result  we  will  get
                                 Equation of kind
                                                dp  d  2  p  d  (n  ) 1   p
                                           ( y ,  , p  ,  ,...,  )   . 0                             (3.14)
                                                dy  dy 2    dy (n  ) 1 

                                     If this equation has the common decision

                                                
                                                    p  (y ,c  ,c  ,...,c  ),                                    (3.15)
                                                       1  2    n  1 

                                             dy
                                 where  p     ,  it  is  enough  to  separate  finding  of  general
                                             dx
                                 integral  variables  in  the  last  equation  and  untie  him  by
                                 integration:
                                          dy
                                                    dx  ,   ,( cy  1 ,c 2 ,...,c n 1 )   x   c n . (3.16)
                                                      
                                    (y ,c  ,c  ,...,c  )
                                        1  2    n 1

                                     If in equation of the considered type of n=2, we come the
                                 offered method at once to equation of the first order:
                                                                          dp
                                 with  F (y ,  y  ,  y  )   0  we will get   y ,  , p  )   , 0  from where
                                                                    (
                                                                          dy
                                 the    common      decision    p   (y ,c  ),    and   farther
                                                                         1
                                     dy
                                           dx ,   ,( cy  1 )   x   c 2  .
                                             
                                    (y ,c  )
                                        1

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