Page 327 - Handbook Of Integral Equations
P. 327

3 . The solution with λ = λ 2 ≠ λ 1 and f 1 = f 2 = 0 is given by the formulas of item 2 in
                      ◦
                                                                                           ◦
                     which one must replace λ 1 and y 1 (x)by λ 2 and y 2 (x), respectively.
                                                                                         2
                      ◦
                     4 . Solution with λ = λ 1,2 = λ ∗ and f 1 = f 2 = 0, where the characteristic value λ ∗ =
                                                                                      (A + B)s 1
                     is double:
                                                 y(x)= f(x)+ Cy ∗ (x),
                     where C is an arbitrary constant and y ∗ (x) is an eigenfunction of the equation corresponding
                     to λ ∗ . Two cases are possible.
                                                        2 2
                        (a) If A ≠ B, then 4ABs 0 s 2 = –(A – B) s and
                                                         1
                                                           (A – B)s 1
                                               y ∗ (x)= g(x) –     .
                                                             2As 0
                                                                 2 2
                        (b) If A = B, then, in view of 4ABs 0 s 2 = –(A – B) s = 0,wehave
                                                                   1
                                               g(x)        for s 0 ≠ 0 and s 2 =0,

                                      y ∗ (x)=  1          for s 0 = 0 and s 2 ≠ 0,
                                                           for s 0 = s 2 =0,
                                               C 1 g(x)+ C 2
                     where C 1 and C 2 are arbitrary constants.

                              b

               7.    y(x) – λ  [Ag(x)+ Bg(t)+ C]h(t) y(t) dt = f(x).
                             a
                     The characteristic values of the equation:

                                                        2 2                 2 2
                                (A + B)s 1 + Cs 0 ±  (A – B) s +2(A + B)Cs 1 s 0 + C s +4ABs 0 s 2
                                                                              0
                                                         1
                          λ 1,2 =                                                       ,
                                                           2
                                                      2AB(s – s 0 s 2 )
                                                           1
                     where
                                     b               b                  b

                                                                          2
                               s 0 =  h(x) dx,  s 1 =  g(x)h(x) dx,  s 2 =  g (x)h(x) dx.
                                    a               a                  a
                      ◦
                     1 . Solution with λ ≠ λ 1,2 :
                                             y(x)= f(x)+ λ[A 1 g(x)+ A 2 ],
                     where the constants A 1 and A 2 are given by
                                                  Af 1 – ABλ(f 1 s 1 – f 2 s 0 )
                                      A 1 =                                  ,
                                                       2
                                               2
                                           AB(s – s 0 s 2 )λ – [(A + B)s 1 + Cs 0 ]λ +1
                                               1
                                               C 1 f 1 + Bf 2 – ABλ(f 2 s 1 – f 1 s 2 )
                                      A 2 =    2                             ,
                                                       2
                                           AB(s – s 0 s 2 )λ – [(A + B)s 1 + Cs 0 ]λ +1
                                               1
                                            b                   b
                                     f 1 =  f(x)h(x) dx,  f 2 =  f(x)g(x)h(x) dx.
                                          a                   a
                     2 . Solution with λ = λ 1 ≠ λ 2 and f 1 = f 2 =0:
                      ◦
                                                                      1 – λ 1 As 1
                                    y(x)= f(x)+ Cy 1 (x),  y 1 (x)= g(x)+      ,

                                                                        λ 1 As 0
                     where C is an arbitrary constant and y 1 (x) is an eigenfunction of the equation corresponding

                     to the characteristic value λ 1 .

                 © 1998 by CRC Press LLC









               © 1998 by CRC Press LLC
                                                                                                             Page 306
   322   323   324   325   326   327   328   329   330   331   332