How Do You Evaluate the Residues in the Cauchy Integral Formula for G_0(u)?

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SUMMARY

The discussion focuses on evaluating the residues in the Cauchy Integral Formula for the function G_0(u) defined as G_0 = (1 - α/u²) / (1 - αu²), where 0 < α < 1. The integral to evaluate is Γ(τ) = (1/2πi) ∮ (ln(G_0(u)) / (u - τ)) du, taken around the unit circle. It is established that G_0 has zeros but no poles within the unit circle, and it possesses a second-order singularity at u = 0. The suggested approach involves using power series expansions, starting with the geometric series for G_0 followed by the series for log(1 + w).

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marcusl
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I have a function
[tex]G_0=\frac{1-\alpha/u^2}{1-\alpha u^2} .[/tex]

Since [tex]0<\alpha<1[/tex], [tex]G_0[/tex] has zeroes but no poles inside the unit circle.

I need to evaluate
[tex]\Gamma(\tau)=\frac{1}{2\pi i}\oint{\frac{\ln{G_0 (u)}}{u-\tau}du}[/tex]
where the integral is around the unit circle. How do I evaluate the poles of the integrand so I can evaluate this using residues?

EDIT: Oops, G0 has a second order singularity at u=0, too.
 
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maybe power series wouldwork, first the geometric series for G0 then the series for log(1+w)?
 

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