1. It is well known that the solution of the ordinary linear differential equation with constant coefficients
(Dn + a1Dn−1 + + an−1D+an)y = F(x), .....(1)
where y, Dy, ..., Dn−1y take arbitrary values y0, y1, .., yn−1
when x = 0, ..... (2)
can be obtained by multiplying (1) by e−px, (p > 0) and integrating with regard to x from 0 to ∞