Wednesday, 26 November 2014

Solving the Integral intinfty0,mathrmarcsinhleft(fracasqrtx2+y2right),mathrmcos(b,x),mathrmdx

Is there any possibily to solve the following integral



0arcsinh(ax2+y2)cos(bx)dx



with a>0, y>0 and π/2<arg(b)<0.



I assume, the result is connected to Bessel and Struve functions. Thank you.



Edit:
Using integration by parts with




cos(bx)dx=sin(bx)b



ddx(arcsinh(ax2+y2))=ax(x2+y2)x2+y2+a2



and the limits



limx0sin(bx)barcsinh(ax2+y2)=0


limxsin(bx)barcsinh(ax2+y2)=0




Gives the integral



0ax(x2+y2)x2+y2+a2sin(bx)bdx



if that makes anything simpler...



Edit2:



Mathematica tells me that the last integrand can be presented as the product of three G-functions. Inhere it is said that the integral of the product of three G-functions can be computed under certain restrictions. Sadly it is not mentioned which restrictions. Does anybody know anything about this?




It would be:



1x2+y2+a2=1πy2+a2MeijerG[{{12},{}},{{0},{}},x2y2+a2]



1x2+y2=1y2MeijerG[{{0},{}},{{0},{}},x2y2]



sin(bx)=πMeijerG[{{},{}},{{12},{0}},x2b24]



which finally results in




ay2y2+a20xMeijerG[{{12},{}},{{0},{}},x2y2+a2]MeijerG[{{0},{}},{{0},{}},x2y2]MeijerG[{{},{}},{{12},{0}},x2b24]dx



The MeijerG are defined according to Mathematica syntax. Or (I hope I converted this correctly)



ay2y2+a20xG1,11,1(120x2y2+a2)G1,11,1(00x2y2)G1,00,2(12,0x2b24)dx

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