Complex Integration Homework: Evaluate Intergral Gamma (y)dz

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The discussion centers on evaluating the integral of a function y over a complex path gamma, defined by line segments from 0 to i and from i to i+2. Participants suggest breaking the integral into two parts, integrating along each segment separately. The first segment can be parameterized as z = (1+i)t, while the second as z = (1+t) + i, with corresponding differentials. A key point raised is the lack of clarity regarding the function y(z), which is essential for completing the evaluation. The conversation emphasizes the importance of understanding path integrals in complex analysis.
kmeado07
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Homework Statement



Evaluate the following intergral:


Homework Equations



Intergral from gamma of (y)dz, where gamma is the union of the line segments joining 0 to i and then i to i+2

The Attempt at a Solution



I have no idea how to do this!
 
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kmeado07 said:
Intergral from gamma of (y)dz, where gamma is the union of the line segments joining 0 to i and then i to i+2

Hi kmeado07! :smile:

(have a gamma: Γ :wink:)

Γ is an L-shaped path …

just integrate along each bit of it separately.

(but what is y? :confused:)
 
Presumably, if you are expected to do a problem like this, you know something about path integrals. The line from 0 to i, in the complex plane, can be written as z= (1+i)t where t ranges from 0 to 1. The line from i to i+ 2 can be written as z= (1+ t)+ i where, again, t ranges from 0 to 1. Do those two integrals separately with z replace by those and dz by (1+i)dt in the first integral and by dt in the second.

Unfortunately, you see to have forgotten to say what the integrand, y(z), is!
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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