Computing the surface integral of a parabloid

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The discussion focuses on understanding the limits of integration for the surface integral of a paraboloid, specifically the region R projected onto the XY plane. The author questions the determination of these limits, particularly the angles θ from π/3 to π/2 and the radius r equal to 1. The shape of R is clarified as being defined by the lines x=0, y=x√3, and the equation 1=x²+y², indicating a circular arc. There is confusion regarding the measurement of θ from the positive x-axis at the straight lines. Ultimately, the complexity of the problem is acknowledged, highlighting the challenges in visualizing and computing the integral.
ainster31
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Homework Statement



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Homework Equations





The Attempt at a Solution



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I am having difficulty understanding how the author determined the limits of integration of ##R##. The author used ##\theta=\pi/3\quad to\quad \theta=\pi/2## and ##r=1\quad to\quad r=1##. More accurately, I'm not even sure how the author graphed ##R## in the diagram. Where did he get the shape of ##R## from?
 
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R is the projection of the paraboloid onto the XY plane. The surface boundary is given in the question by the lines x=0, y = x√3, z=1. Since 2z = 1 + x2+y2 for the surface, that last translates into 1 = x2+y2 for R. So R's boundary consists of two straight lines and an arc of a circle.
If θ is measured from the +ve x-axis, what are its values at the two straight lines?
 
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haruspex said:
If θ is measured from the +ve x-axis, what are its values at the two straight lines?

Well Haruspex! I'm shocked, SHOCKED!
 
LCKurtz said:
Well Haruspex! I'm shocked, SHOCKED!
Only if you touch the -ve at the same time?
 
Edit: never mind.
 
Last edited:
Edit: never mind again.
 
OK, I think I got it, but that was ridiculously complicated.
 

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