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Differential and Integral Equation




                    Notes
                                   Now if  a 1  0,  then we have

                                            y =     a x r
                                                     r
                                                 r  0
                                               = a 0  a x a x 2  a x  3
                                                     1
                                                              3
                                                         2
                                                      2   2  2 2  (  2)  4  ( 2) m  (  2)  (  2 m  2)  2m
                                               = a 0  1  x           x                           x
                                                                                     m
                                                       2!       4!                  (2 )!
                                                                  2
                                                        2(  1)  3  2 (  1)(  3)  5
                                                  a x         x              x
                                                   1
                                                          3!          5!
                                                     m
                                                 ( 2) (  1)(  3) (   2m  1)  2m  1
                                                                          x                              ...(viii)
                                                          (2m  1)!
                                   and if a  = 0, then we have
                                        1
                                                      2   2  2 2  (  2)  4  ( 2) m  (  2) (  2m  2)  2m
                                            y =  a 0  1  x           x                           x         ...(ix)
                                                       2!       4!                  (2 )!
                                                                                     m
                                               = y  (say).
                                                  1
                                   Case II: When k = 1, from (vi), we have

                                                                   2(r  1) 2
                                                            a    =           a r .
                                                             r  2  (r  3)(r  2)

                                   Putting r = 1, 3, ... etc.
                                                              a  = a  = ... = 0 (each).
                                                               3    5
                                   Since in this case from (iv), a  = 0
                                                         1
                                   Putting r = 0, 2, 4, ... etc.

                                                                   2 2       2(  1)
                                                              a  =      a 0        a 0
                                                               2     3.2       3!
                                                                   6 2      2(  1)(  3)
                                                              a  =      a 2            a 0
                                                               4     5.4         3!
                                   and so on.

                                                                       m
                                                                   ( 2) (  1)(  3) (   2m  1)
                                                             a   =                          a 0
                                                              2m            (2m  1)!
                                       we have


                                                    y =    a x r  1
                                                            r
                                                         r  0
                                                      = a x a x 3  a x  5  a x  2m  1
                                                         0   2    4       2m


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