Page 328 - Handbook Of Integral Equations
P. 328

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.
                     4 . Solution with λ = λ 1,2 = λ ∗ and f 1 = f 2 = 0, where the characteristic value λ ∗ =
                      ◦
                           2
                                   is double:
                     (A + B)s 1 + Cs 0
                                                 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
                        (a) If As 1 – (Bs 1 + Cs 0 ) ≠ 0, then 4As 0 (Bs 2 + Cs 1 )= –[(A – B)s 1 – Cs 0 ] and
                                                         (A – B)s 1 – Cs 0
                                            y ∗ (x)= g(x) –           .
                                                             2As 0
                                                                                       2
                        (b) If (A – B)s 1 = Cs 0 , then, in view of 4As 0 (Bs 2 + Cs 1 )= –[(A – B)s 1 – Cs 0 ] =0, we
                     have
                                             g(x)        for s 0 ≠ 0 and Bs 2 = –Cs 1 ,

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


                              b

               8.    y(x) – λ  [A + B(x – t)h(t)]y(t) dt = f(x).
                             a
                     The characteristic values of the equation:

                                                                        2
                                                                            2
                                                             2
                                   A(b – a) ±  [A(b – a) – 2Bh 1 ] +2Bh 0 [A(b – a ) – 2Bh 2 ]
                              λ 1,2 =                                                ,
                                                                      2
                                         B A(b – a)[2h 1 – (b + a)h 0 ] – 2B(h – h 0 h 2 )
                                                                      1
                     where
                                        b               b                 b
                                                                           2
                                 h 0 =  h(x) dx,  h 1 =  xh(x) dx,  h 2 =  x h(x) dx.
                                      a               a                 a
                      ◦
                     1 . Solution with λ ≠ λ 1,2 :
                                              y(x)= f(x)+ λ(A 1 + A 2 x),
                     where the constants A 1 and A 2 are given by
                                                
               1     2  2
                                           f 1 – λ B(f 1 h 1 + f 2 h 2 ) – Af 2 (b – a )
                                                                2
                            A 1 =          
    1             2                       ,
                                                                        2
                                 B A(b – a) h 1 – (b + a)h 0 – B(h – h 0 h 2 ) λ + A(b – a)λ +1
                                                2             1
                                             f 2 – λ[A(b – a)f 2 – B(f 1 h 0 + f 2 h 1 )]
                            A 2 =          
                                          ,
                                                              2
                                                1
                                 B A(b – a) h 1 – (b + a)h 0 – B(h – h 0 h 2 ) λ + A(b – a)λ +1
                                                                        2
                                                2             1
                                      b            b                      b

                              f 1 = A  f(x) dx – B  xf(x)h(x) dx,  f 2 = B  f(x)h(x) dx.
                                     a            a                      a
                      ◦
                     2 . Solution with λ = λ 1 ≠ λ 2 and f 1 = f 2 =0:
                                                               2 – 2λ 1 [A(b – a) – Bh 1 ]
                               y(x)= f(x)+ Cy 1 (x),  y 1 (x)=1 +                  x,
                                                                         2
                                                                     2
                                                               λ 1 [A(b – a ) – 2Bh 2 ]
                     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 307
   323   324   325   326   327   328   329   330   331   332   333