Find the area enclosed by the curve y = x csch(x+y)

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Discussion Overview

The discussion centers around determining the area enclosed by the curve defined by the equation ##y = x \text{ csch}(x+y)## and the positive ##x##-axis. Participants explore various methods to analyze the curve, including graphical approaches and nested function representations.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant expresses difficulty in solving for ##y## or ##x## directly from the equation and proposes representing it as a nested function, suggesting that the area might approach ##1.5## square units based on numerical integration.
  • Another participant points out that the equation can be reformulated as ##F(x, y) = x - x \text{ csch}(x + y)##, indicating that the graph represents a surface in three-dimensional space, with the area of interest being the cross-section where ##z = 0##.
  • There is mention of discontinuities occurring at points where ##x + y = k\pi##, where ##k## is an integer, which may affect the analysis of the curve.
  • One participant suggests using WolframAlpha to create and integrate a nested form of the function for better area estimation, indicating a lack of familiarity with the necessary programming language.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to accurately determine the area. There are multiple approaches discussed, but no definitive method is agreed upon.

Contextual Notes

Participants note challenges in solving the equation directly and the implications of the nested function structure, which complicates finding a closed-form solution for the area.

Saracen Rue
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TL;DR
Determine the area enclosed by the curve ##y=x \text{ csch}(x+y)## and the positive ##x##-axis
The title and summary pretty much say it all. I was wondering if it's possible to accurately determine the area enclosed by the curve ## y=x \text{ csch}(x+y)## and the ##x##-axis?

I first tried solving for ##y## and then ##x##, however it doesn't appear possible to solve for either variable. I then recognised that the equation can be represented as a nested function, such that: $$f(x)=x \text{ csch}(x+x\text{ csch}(x+x\text{ csch}(x+x\text{ csch}(x+...))))$$

Through this I was able to use Desmos Graphing calculator to help me estimate the enclosed area to by integrating ##f(x)## from ##0## to ##\infty##. However, the imbeded nature of the function made it hard to properly find a definitive solution and I could only gather that the area appears to be approaching ##1.5## square units, although this might be inaccurate and it could be simply approaching a number near ##1.5##.

How would I go about accurately determining this area?
Any help is greatly appreciated.
 
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Saracen Rue said:
Summary:: Determine the area enclosed by the curve ##y=x \text{ csch}(x+y)## and the positive ##x##-axis

The title and summary pretty much say it all. I was wondering if it's possible to accurately determine the area enclosed by the curve ## y=x \text{ csch}(x+y)## and the ##x##-axis?

I first tried solving for ##y## and then ##x##, however it doesn't appear possible to solve for either variable. I then recognised that the equation can be represented as a nested function, such that: $$f(x)=x \text{ csch}(x+x\text{ csch}(x+x\text{ csch}(x+x\text{ csch}(x+...))))$$

Through this I was able to use Desmos Graphing calculator to help me estimate the enclosed area to by integrating ##f(x)## from ##0## to ##\infty##. However, the imbeded nature of the function made it hard to properly find a definitive solution and I could only gather that the area appears to be approaching ##1.5## square units, although this might be inaccurate and it could be simply approaching a number near ##1.5##.

How would I go about accurately determining this area?
Any help is greatly appreciated.
Your equation is equivalent to ##F(x, y) = 0##, with ##F(x, y) = x - xcsch(x + y)##. As such, the graph of F is a surface in ##\mathbb R^3##, and the equation you're working with is the cross-section of the surface in the x-y plane, i.e., where z = 0.
As far as how you would graph F(x, y) = 0, nothing comes to mind, except possibly calculating function values at a bunch of points. There are going to be discontinuities at points where ##x + y = k\pi##, k an integer.
 
Mark44 said:
As far as how you would graph F(x, y) = 0, nothing comes to mind
I think that was already done. Wolfram plots:
1587854000815.png
Re: points where x+y=kπ ? it's hyperbolic: $$y = {x\over \sinh(x+y)}$$
 
BvU said:
I think that was already done. Wolfram plots:
View attachment 261445Re: points where x+y=kπ ? it's hyperbolic: $$y = {x\over \sinh(x+y)}$$
Sorry for not being clear in the OP. You're right, I do already have the graph of ##y=x \text{ csch}(x+y)## and I'm just trying to find the area enclosed by the cruve and the ##x##-axis

Edit: Do you think it would be possible to use WolframAlpha's nest function to create and integrate a heavily nested form of ##y=x\text{ csch}(x+x\text{ csch}(x+...))## to allow for a better estimation of the area? I tried doing it myself but I'm not the most familiar with the language and could only seem to get it to nest every variable ##x## with ##y(x)##
 
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