(adsbygoogle = window.adsbygoogle || []).push({}); Need help with complex problems!!

I have trouble with a residue problem:

Integral -inf --> inf sin(ax)/(x^2 + 4x + 5)

As both it's poles contains both a real and a complex side, the sin(ax) part gets very ugly when I try to calculate it's residues. And I get a complex answere! Do I just ignore the complex part of the answere, and why?

Also, I can't figure out how to make a laurentseries out of:

1/(1-cos(x))

Thanx for any help!!

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# Homework Help: Need help with complex problems

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