Question: How to evaluate this integral using residues∫∞0xsinx1+x2dx
I integrate over the entire real axis and dividing it by 1/2 since the integrand is even, and then I do the thing with the turning it into −Im(∫f⋅eixdx) and integrate over the upper half plane by finding the residues there, and there's only one, at i.
So I put it into the equation xeiz2x and get 12e, so I get when plugging that in
∫∞0xsinx1+x2dx=.5∫∞−∞xsinx1+x2dx=.5−Im[2πi⋅Res(xeix1+x2;i)]=.5⋅[−Im(2πi⋅12e)]=−π2e
But the answer's positive.
What did I mess up on?
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