- #1
Shackleford
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- 2
Homework Statement
Use the first example in Lecture 38 to evaluate [itex] \int_{0}^{2\pi} cost\: sint \:dt [/itex]
http://s8.postimg.org/ccycky76d/Screen_Shot_2015_04_25_at_9_47_41_PM.png
Homework Equations
Residue theorem, etc.
The Attempt at a Solution
I mostly understand his work in the example. On a side note, it seems that his notes are a bit terse, but I digress.
I understand the application of the Residue Theorem around the closed path. The upper half circle includes the removable singularity z = i. He integrated around the two half circle paths using z = Reiθ, dz =Rieiθdz and z = reiθ, dz = rieiθdz substitutions. I assume that limits of integration for f(z) = f(reiθ) are π to 0 to complete the path circumscribing the difference between the two upper half circles. For the segment integral -R to -r, why is πi in the numerator? And he equated them to segment integral r to R because of symmetry?