Evaluation of some non-elementary integrals involving sine, cosine, exponential and logarithmic integrals: Part I
Classical Analysis and ODEs
2018-08-02 v2
Abstract
The non-elementary integrals Siβ,α=∫[sin(λxβ)/(λxα)]dx,β≥1,α≤β+1 and Ciβ,α=∫[cos(λxβ)/(λxα)]dx,β≥1,α≤2β+1, where {β,α}∈R, are evaluated in terms of the hypergeometric functions 1F2 and 2F3, and their asymptotic expressions for ∣x∣≫1 are also derived. The integrals of the form ∫[sinn(λxβ)/(λxα)]dx and ∫[cosn(λxβ)/(λxα)]dx, where n is a positive integer, are expressed in terms Siβ,α and Ciβ,α, and then evaluated. Siβ,α and Ciβ,α are also evaluated in terms of the hypergeometric function 2F2. And so, the hypergeometric functions, 1F2 and 2F3, are expressed in terms of 2F2.The exponential integral Eiβ,α=∫(eλxβ/xα)dx where β≥1 and α≤β+1 and the logarithmic integral Li=∫μxdt/lnt,μ>1 are also expressed in terms of 2F2, and their asymptotic expressions are investigated. It is found that for x≫μ, Li∼x/lnx+ln(lnμlnx)−2−lnμ2F2(1,1;2,2;lnμ), where the term ln(lnμlnx)−2−lnμ2F2(1,1;2,2;lnμ) is added to the known expression in mathematical literature Li∼x/lnx.
Cite
@article{arxiv.1703.01907,
title = {Evaluation of some non-elementary integrals involving sine, cosine, exponential and logarithmic integrals: Part I},
author = {Victor Nijimbere},
journal= {arXiv preprint arXiv:1703.01907},
year = {2018}
}
Comments
23 pages, 1 figure, Accepted for publication by the Ural Math. J