Thursday, 13 August 2015

calculus - Tough integral with coth[1/u]

I'm hoping to come up with an analytical solution for the following definite integral:




2/y2/yucoth(1u)icot(z2)du



Here, y and z are strictly positive real constants. i is the imaginary number 1.



I tried doing this on Mathematica but it's been 20 minutes and it hasn't given me anything yet. I was wondering if anybody had any tricks/tips for solving this integral?



Thanks!



EDIT: The imaginary component can be eliminated as follows:




2/y2/yucoth(1u)icot(z2)du=2/y2/yucoth(1u)coth2(1u)+cot2(z2)du+i2/y2/yucot(z2)coth2(1u)+cot2(z2)du
The second integral is odd, so it evalutes to zero. Thus,
2/y2/yucoth(1u)icot(z2)du=2/y2/yucoth(1u)coth2(1u)+cot2(z2)du
However, I don't think this is any easier to solve...



EDIT2: As noted by the comments, it might be a bit nicer if I set b=2/y and c=cot(z/2) so that my integral looks like:



bbucoth(1u)icdu=bbucoth(1u)coth2(1u)+c2du

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