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b
               29.   y(x)+ A    te λ|x–t| y(t) dt = f(x).
                              a
                     This is a special case of equation 4.9.37 with g(t)= At. The solution of the integral equation
                     can be written via the Bessel functions (or modified Bessel functions) of order 1/3.

                             ∞
               30.   y(x)+     (a + b|x – t|) exp(–|x – t|)y(t) dt = f(x).
                            0
                                                     4
                                                                 2
                     Let the biquadratic polynomial P(k)= k +2(a – b +1)k +2a +2b + 1 have no real roots and
                     let k = α + iβ be a root of the equation P(k) = 0 such that α > 0 and β > 0. In this case, the
                     solution has the form

                                              ∞
                                y(x)= f(x)+ ρ   exp(–β|x – t|) cos(θ + α|x – t|)f(t) dt
                                             0
                                                 2 2
                                       [α +(β – 1) ]     ∞
                                      +                 exp[–β(x + t)] cos[α(x – t)]f(t) dt
                                           4α β      0
                                             2

                                        R    ∞
                                      +        exp[–β(x + t)] cos[ψ + α(x + t)]f(t) dt,
                                       4α 2  0
                     where the parameters ρ, θ, R, and ψ are determined from the system of algebraic equations
                     obtained by separating real and imaginary parts in the relations
                                                µ          iψ   (β – 1 – iα) 4
                                          iθ
                                        ρe  =       ,    Re  =            .
                                                                  2
                                              β – iα            8α (β – iα)
                     •
                       Reference: F. D. Gakhov and Yu. I. Cherskii (1978).

               4.3. Equations Whose Kernels Contain Hyperbolic
                      Functions

                 4.3-1. Kernels Containing Hyperbolic Cosine

                              b

               1.    y(x) – λ  cosh(βx)y(t) dt = f(x).
                             a
                     This is a special case of equation 4.9.1 with g(x) = cosh(βx) and h(t)=1.

                                b
               2.    y(x) – λ  cosh(βt)y(t) dt = f(x).
                             a
                     This is a special case of equation 4.9.1 with g(x) = 1 and h(t) = cosh(βt).

                              b

               3.    y(x) – λ  cosh[β(x – t)]y(t) dt = f(x).
                             a
                     This is a special case of equation 4.9.13 with g(x) = cosh(βx) and h(t) = sinh(βt).
                        Solution:

                                       y(x)= f(x)+ λ A 1 cosh(βx)+ A 2 sinh(βx) ,
                     where A 1 and A 2 are the constants determined by the formulas presented in 4.9.13.




                 © 1998 by CRC Press LLC









               © 1998 by CRC Press LLC
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