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a


               13.        k sinh(λx) – t y(t) dt = f(x).

                      0
                     This is a special case of equation 3.8.5 with g(x)= k sinh(λx).
                       a


               14.        x – k sinh(λt) y(t) dt = f(x).

                      0
                     This is a special case of equation 3.8.6 with g(x)= k sinh(λt).
                 3.3-3. Kernels Containing Hyperbolic Tangent

                       b


               15.        tanh(λx) – tanh(λt) y(t) dt = f(x).

                      a
                     This is a special case of equation 3.8.3 with g(x) = tanh(λx).
                        Solution:
                                                            2


                                            y(x)=  1 d   cosh (λx)f (x) .
                                                                  x
                                                  2λ dx
                     The right-hand side f(x) of the integral equation must satisfy certain relations (see item 2 of
                                                                                           ◦
                     equation 3.8.3).
                       a


               16.        tanh(βx) – tanh(µt) y(t) dt = f(x),  β >0,  µ >0.

                      0
                     This is a special case of equation 3.8.4 with g(x) = tanh(βx) and λ = µ/β.
                         b
                             k       k
               17.      | tanh x – tanh t| y(t) dt = f(x),  0 < k <1.
                      0
                                                                 k
                     This is a special case of equation 3.8.3 with g(x) = tanh x.
                        Solution:
                                                1 d      2      k–1

                                         y(x)=        cosh x coth  xf (x) .
                                                                     x
                                               2k dx
                     The right-hand side f(x) must satisfy certain conditions. As follows from item 3 of equation
                                                                                    ◦
                     3.8.3, the admissible general form of the right-hand side is given by

                            f(x)= F(x)+ Ax + B,    A = –F (b),  B =  1    bF (b) – F(0) – F(b) ,


                                                         x         2   x
                     where F(x) is an arbitrary bounded twice differentiable function (with bounded first deriva-
                     tive).
                       b
                                y(t)
               18.                          dt = f(x),   0 < k <1.
                      a |tanh(λx) – tanh(λt)| k
                     This is a special case of equation 3.8.7 with g(x) = tanh(λx)+ β, where β is an arbitrary
                     number.
                       a


               19.        k tanh(λx) – t y(t) dt = f(x).

                      0
                     This is a special case of equation 3.8.5 with g(x)= k tanh(λx).
                       a


               20.        x – k tanh(λt) y(t) dt = f(x).

                      0
                     This is a special case of equation 3.8.6 with g(x)= k tanh(λt).
                 © 1998 by CRC Press LLC







               © 1998 by CRC Press LLC
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