A First Course in Complex Analysis · Problem 29

Consequences of Cauchy's Theorem — Beck, Marchesi, Pixton & Sabalka

Mathematics — Complex Analysis · cauchys-theorem

Problem

Show that ∫C[0,2]dzz3+1=0\int_{C[0,2]} \frac{dz}{z^3 + 1} = 0 by arguing that this integral does not change if we replace C[0,2]C[0,2] by C[0,r]C[0,r] for any r>1r > 1, then use Proposition 4.1.8 Item d to obtain an upper bound for ∣∫C[0,r]dzz3+1∣\left|\int_{C[0,r]} \frac{dz}{z^3+1}\right| that goes to 00 as r→∞r \to \infty.

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