Page 18 - 4549
P. 18

General integral, taking into account, that, we will get in a
                                              2
                                 kind  x              C
                                            x   y
                                          tg      1
                                              2
                                     .
                                     2) Lets  sin t  1   . 0
                                                            
                                     Then  sint     , 1  t       2 k  , k   . Z  As  x   y   t , so we
                                                            2
                                              
                                 get   x   y       2 k  , k   . Z 
                                               2

                                          Exercises:

                                      1.  To define the order of differential equations :
                                                                          5
                                                                    3
                                                                  2
                                                       0
                                      )a  y 3  sin ''y   xy  '  ;        )б  x y   3x y  ' y  2    0.
                                      2.  To check  or the functions indicated below are the upshots
                                 of the proper differential equations :
                                        2
                                                                                       a
                                                                                    '
                                      )а y   2 (a x   ) k ( k і a -  constants ) ;  equation  yy   ;
                                      )б y   Ce  2x  (C - constant ) ;   ' 2y   y   4x equation  .
                                      3.  To check or written expressions are the general integrals
                                 of differential equation :
                                                                                2x   y
                                                             2
                                                     2
                                           2
                                        )a  x   xy   y   9 C    ;    equation  'y     ;
                                                                                x   2y
                                                                             x
                                                2
                                           2
                                        )б  x   y   4 C  2  ;    equation  'y     .
                                                                             y
                                      4.  To  find  differential  equation,  the  common  decision  of
                                 which the crooked are, set by equations:
                                       ) a y   Cxe x  ;
                                                   C
                                       ) б y   C x   2  .
                                               1
                                                    x


                                                               16
   13   14   15   16   17   18   19   20   21   22   23