Help with Multivariable Calculus

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SUMMARY

The discussion centers on calculating the average area of an inscribed triangle within a unit circle, where each vertex is randomly positioned on the circle. The maximum area of an equilateral triangle is established as 3√3/4, with the challenge being to compare this maximum to the average area. A hint is provided to simplify the problem using polar angles θ1 and θ2 for the triangle's vertices, emphasizing the need to determine the region of integration based on these angles.

PREREQUISITES
  • Understanding of multivariable calculus concepts
  • Familiarity with polar coordinates
  • Knowledge of double integrals
  • Basic geometry of triangles and circles
NEXT STEPS
  • Study the calculation of double integrals in polar coordinates
  • Explore the properties of inscribed triangles in circles
  • Investigate the relationship between maximum and average areas of geometric shapes
  • Learn about the application of integration in probability theory
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Students and educators in mathematics, particularly those focused on calculus, geometry, and probability, will benefit from this discussion.

CDrappi
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Find the average area of an inscribed triangle in the unit circle. Assume that each vertex of the triangle is equally likely to be at any point of the unit circle and that the location of one vertex does not affect the likelihood the location of another in any way. (Note that, as seen in Problem set 4, the maximum area is achieved by the equilateral triangle, which has
side length √3 and area 3√3/4. How does the maximum compare to the average?)
Hint: in order to reduce the problem to the calculation of a double integral, place one of the vertices of the triangle at(1,0),and use the polar angles θ1 and θ2 of the two other vertices as variables. What is the region of integration?

Thanks

http://ocw.mit.edu/NR/rdonlyres/Mathematics/18-02Fall-2007/Assignments/ps7.pdf

(I'm not at MIT, I'm taking the class online, and this problem REALLY irritated me)
 
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If this is HW, it should have been posted under the HW forums.

Do you have a specific question? The region of integration is given by the domain of the integration variables, θ1 and θ2. Picture one side of the triangle making a sweep inside the unit circle (sort of like a radar monitor) -- what is the minimum angle? What is the max. angle?
 
EnumaElish said:
If this is HW, it should have been posted under the HW forums.

Do you have a specific question? The region of integration is given by the domain of the integration variables, θ1 and θ2. Picture one side of the triangle making a sweep inside the unit circle (sort of like a radar monitor) -- what is the minimum angle? What is the max. angle?

It isn't homework... as I'm not in a class. But it is a "problem," so I actually reposted it in the HW section.
 

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