I'm being asked to integrate $f(z) = \frac{e^z}{z^2 + 2z + 1}$ around a $5 \times 5$ square, centered at $i$, in the counter clockwise direction. It seems to me that applying Cauchy's integral formula for the first derivative directly yields an answer, but I am concerned the approach is incorrect due to a double pole at $z =-1$. Is there any special case that I am missing?
2026-04-24 19:43:30.1777059810
Proper application of Cauchy integral formula
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Cauchy's differentiation formula states: $$ f^{(n)}(a) = \frac{n!}{2 \pi i} \oint_\gamma \frac{f(z)}{(z-a)^{n+1}} \mathrm{d} z $$ In the case at hand, $a=-1$, $n=1$, $f(z) = \mathrm{e}^z$. Hence $$ \oint_\gamma \frac{\mathrm{e}^z}{z^2 + 2 z + 1} \mathrm{d} z = 2 \pi i \mathrm{e}^{-1} $$