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From  the  geometrical  point  of  view  common  decision
                                  y    Cx,    is  one  parametric  family  of  lines    where  C   is
                                 parameter and partial decision  y     , Cx   is one of the lines
                                                                         0
                                 of  this  family  (unique)  that  passes  through  point  M 0  , yx 0  0 
                                 which  belongs  to  the  region  D .  Exactly  equation  (1.3)
                                 determines  the  angular  coefficient  of  tangent  to  the  integral
                                 curve that passes through point   yxM ,  ,  k   y     f   yx,  .
                                                                               M
                                      Consequently,  if  the
                                 examine    f  (x .y )   as  a
                                 function  with  respect  of
                                 coordinates  x   and  y   of
                                 the  point  M  (x ,  ) y   that
                                 belongs to  the  region  D
                                 of equation (1.3)  puts in
                                 according  to  every  point
                                 of  domain  region  D
                                 defined     value     of              Fig. 1.1
                                 derivative  y   from  the
                                 function  y   after  that  is
                                 direction  of  the  proper
                                 integral  curve  in  this
                                 point.  Thus  Cauchy  task
                                 (1.6)   can    be   now
                                 interpreted   from    the
                                 geometrical point of view
                                 that  it  is  necessary  to
                                 build so a curve L which
                                 would pass through point
                                 M  (Fig. 1.1) the tangent
                                    0
                                 to  which  in  any  point
                                 would  have  direction,
                                 that   coincides    with              Fig. 1.2

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