Finding an upper bound for a contour integral (Complex)

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SUMMARY

The discussion focuses on finding an upper bound for the contour integral of \(\int e^{2z} - z^2 \, dz\) using the ML inequality. The contour consists of two parts: C1, a circular arc from point A \((\sqrt{3}/2, 1/2)\) to B \((1/2, \sqrt{3}/2)\), and C2, a line segment from the origin to B. The lengths of the contours were calculated as \(\pi/6\) for C1 and \(1\) for C2. The user successfully applied the triangle inequality to estimate \(|e^{2z} - z^2|\) but encountered difficulties in determining the upper bound for \(|e^{2z}|\).

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  • Knowledge of parameterization of curves in the complex plane
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C1 1. Homework Statement :
Using the ML inequality, I have to find an upper bound for the contour integral of \int e^2z - z^2 \, dz
where the contour C = C1 + C2.

C1 is the circular arc from point A(sqrt(3)/2, 1/2) to B(1/2, sqrt(3)/2) and C2 is the line segment from the origin to B.


Homework Equations

The Attempt at a Solution



I figured I have to find M1 and M2, and also L1 and L2 given the two different contours. Along C1, I have found the length to be pi/6 by integrating a parameterized equation of the unit circle from pi/6 to pi/3. I have also found the length along C2 to be 1 (no surprises here)

However, I've hit a bump when trying to find the upper bound for e^2z - z^2.
I figured I should use the triangle inequality i.e. |e^2z - z^2|
<= |e^2z| + |-z^2|
= |e^2z| + |z^2|
= |e^2z| + |z|^2
= |e^2z| + 1 (since the length of the line segment is one).

I'm kind of stuck when it comes to the e^2z. It's the same problem for finding the upper bound on C2 as well.

I'm sorry for not using Latex. I tried formatting it but it doesn't come out as intended in the Preview, so I decided not to take the risk of fudging it up and making it look confusing. I'm quite sleepy, sorry.
[/B]
 
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If z = x + iy then e^z = e^x (\cos y + i \sin y)...
 
pasmith said:
If z = x + iy then e^z = e^x (\cos y + i \sin y)...
Thank you so much, I've got it :)
 

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