Page 276 - Handbook Of Integral Equations
P. 276

b
                                        3
                                   3
               22.   y(x) – λ  (Ax + Bt )y(t) dt = f(x).
                             a
                     The characteristic values of the equation:

                                 1              1       2  2  4
                                                           4
                                 4  (A + B)∆ 4 ±  16  (A – B) ∆ + AB∆ 1 ∆ 7       n   n
                                                              7
                            λ 1,2 =                                    ,    ∆ n = b – a .
                                                       1
                                                    2
                                          2AB    1  ∆ – ∆ 1 ∆ 7
                                                16  4  7
                     1 . Solution with λ ≠ λ 1,2 :
                      ◦
                                                               3
                                              y(x)= f(x)+ λ(A 1 x + A 2 ),
                     where the constants A 1 and A 2 are given by
                                                             1
                                                Af 1 – ABλ  f
                                     A 1 =        1   1    4 1 ∆ 4 – f 2 ∆ 1  ,

                                                               1
                                                   2
                                         ABλ  2   ∆ – ∆ 1 ∆ 7 – λ(A + B)∆ 4 +1
                                                16  4  7       4
                                                            1     1
                                               Bf 2 – ABλ  f
                                                                  7
                                     A 2 =        1   1   4 2 ∆ 4 – f 1 ∆ 7   ,

                                                               1
                                                   2
                                         ABλ  2   ∆ – ∆ 1 ∆ 7 – λ(A + B)∆ 4 +1
                                                16  4  7       4
                                                b               b
                                                                 3
                                         f 1 =  f(x) dx,  f 2 =  x f(x) dx.
                                              a               a
                     2 . Solution with λ = λ 1 ≠ λ 2 and f 1 = f 2 =0:
                      ◦
                                                                           4
                                                                              4
                                                                   4 – λ 1 A(b – a )
                                                                3
                                  y(x)= f(x)+ Cy 1 (x),  y 1 (x)= x +           ,
                                                                     4λ 1 A(b – a)
                     where C is an arbitrary constant and y 1 (x) is an eigenfunction of the equation corresponding
                     to the characteristic value λ 1 .
                     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.
                                                                            8
                     4 . Solution with λ = λ 1,2 = λ ∗ and f 1 = f 2 = 0, where λ ∗ =  is the double
                      ◦
                                                                              4
                                                                                  4
                                                                      (A + B)(b – a )
                     characteristic value:
                                                                               4
                                                                           4
                                                                   (A – B)(b – a )
                                                                3
                                  y(x)= f(x)+ Cy ∗ (x),  y ∗ (x)= x –           ,
                                                                      8A(b – a)
                     where C is an arbitrary constant and y ∗ (x) is an eigenfunction of the equation corresponding
                     to λ ∗ .
                                b
                                  2
                                     3
               23.   y(x) – λ  (xt – t )y(t) dt = f(x).
                             a
                                                                             2
                     This is a special case of equation 4.9.8 with A =0, B = 1, and h(t)= t .
                        Solution:
                                              y(x)= f(x)+ λ(A 1 + A 2 x),
                     where A 1 and A 2 are the constants determined by the formulas presented in 4.9.8.
                 © 1998 by CRC Press LLC








               © 1998 by CRC Press LLC
                                                                                                             Page 255
   271   272   273   274   275   276   277   278   279   280   281