In formula Kramers-Kronig 82,9 Landau - Lifgarbages page 390 volume 8 for dielectric permeability have added 2 composed 4*pisigma/W (omega) which is responsible for a pole in zero in a conductor. A question: the First part of imaginary dielectric permeability E’’(w)=-1/pi*∱E’(w’)/(w’-w) dw’ where E-dielectric permeability should remain constant, but in it was gone-1 why, and hardly above in the formula 82,7 for dielectric was not gone-1? The question of the teacher in that that it was not necessary but if who can prove that it influences something or something depends on it will be plus:). Using any materials. Here were, what variants: " On the mathematician the conclusion assumes to neglect integral on infinite to a floor of a circle for what from function subtract its value on infinity, and it just (see at the same LL) 1. " On other that due to-1 integral to converge better and it is not necessary to look what frequency, here, if it is possible to become more in detail at which frequencies noticeably participation-1 If it is possible write the variants as can influence-1 physically, mathematical, for example if all таки with-1 to converge better that it is possible to paint if not difficultly or to give the reference to the literature where is painted, simply the teacher should to something be shown, that-1 is though any sense, instead of in words. In advance ALL THANKS.