- #1
oddiseas
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Homework Statement
1)a Let D = C\{-i,i} and let γ be a closed contour in D. Find all the possible
values of :
(∫(1/(1+z²))dz around γ)
b)
If σ is a contour from 0 to 1, determine all possible
values of:
(∫(1/(1+z²))dz ( around σ)
Homework Equations
The Attempt at a Solution
for part a the denominator factorises to (z+i)(z-i). Now these points are NOT in the domain. If they are not in the domain does that mean i can't evaluate the integral or does it mean that i can evaluate the integral because the points i and -i are discontinuities, but since f(z) is analytic in the domain i can evaluate it and it should give me zero, by cauchys theorm. Anyway when i evaluate it i get the following:
((-1)/(2i)){∫(1/(z+i))-∫(1/(z-i)) and this gives me zero but i am not sure if i am right.
b)
If σ is a contour from 0 to 1, determine all possible
values of:
(∫(1/(1+z²))dz ( around σ)
I am not sure how to try this, or how to represent a contour from zero to 1. Should the contour be a quarter circle moving clockwise, or should it be a line on the real axis? or doesn't it matter what contour i use as long as the endpoints agree. When i calcvulated this using the partial fraction representation above i get zero again. So i think i am stuffing up somewhere. Can someone show me the procedure they use forevaluating these integrals