Alhazen's Billard Problem: Solving a Geometric Puzzle with Algebra

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Discussion Overview

The discussion revolves around Alhazen's Billiard Problem, specifically addressing the challenges of solving it using compass and straightedge constructions. Participants explore the geometric and algebraic implications of the problem, questioning the necessity of cube root extraction and the validity of proposed solutions.

Discussion Character

  • Debate/contested
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • Some participants express confusion about the impossibility of solving the problem with compass and straightedge, suggesting that a bisecting line could yield a solution.
  • Others argue that cube root extraction is indeed necessary for the problem, drawing parallels to historical mathematical challenges like the trisection of an angle and the doubling of the cube.
  • A participant asserts that cube root extraction is not required for this specific problem, prompting questions about the basis for this claim.
  • There is a call for more reliable explanations and diagrams to clarify the formula used in the problem, indicating a lack of understanding among some participants.
  • One participant suggests that the solution involves expressing the equality of two chords algebraically, referencing knowledge from Algebra II.

Areas of Agreement / Disagreement

Participants do not reach consensus on the necessity of cube root extraction for solving the problem. There are competing views regarding the validity of proposed methods and the clarity of the existing explanations.

Contextual Notes

Some participants indicate that the lack of diagrams and clear explanations contributes to misunderstandings about the problem and its solution. The discussion reflects varying levels of familiarity with the mathematical concepts involved.

FulhamFan3
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Alhazen Billiard Problem

I don't get why this problem is impossible with compass/straightedge construction.

I mean can't you draw a line bisecting the two points and where that line meets the circle is the point on the circle your looking for?

I'm probably understanding this problem wrong.
 
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FulhamFan3 said:
Alhazen Billiard Problem
I don't get why this problem is impossible with compass/straightedge construction.
I mean can't you draw a line bisecting the two points and where that line meets the circle is the point on the circle your looking for?
I'm probably understanding this problem wrong.

It says right there on the page.It would imply extraction of cube root.It's the same as other problems in th history of mathematics and especially the trisection of an angle and the famous Delic problem,the one with the doubling of the cube.
Try searching for this problem to the referenced bibliography (the 3 books mentioned there).I'm sure you'll e given a plausible mathematically rigurous explnation.

Daniel.
 
I know a cube root extraction is impossible with compass and straightedge. I'm arguing that it isn't necessary for this problem.
 
FulhamFan3 said:
I know a cube root extraction is impossible with compass and straightedge. I'm arguing that it isn't necessary for this problem.

On what grounds??Do you think the guy who posted this reason on 'wolfram' site was an imbecil??Or the guys who wrote the books he inspired from??Maybe so,but you'd better come up with something reliable instead of his bull****.

Daniel.
 
I mean can't you draw a line bisecting the two points and where that line meets the circle is the point on the circle your looking for?

Try it. (Make sure to set up an asymmetric problem so you don't get lucky!)
 
On what grounds?

Or maybe, just maybe, FulhamFan3 is trying to learn something? Please tone down your attitude.
 
I figured out what I was doing wrong that would make my solution invalid. The site has no diagram showing what they did to get that formula. I had no idea how they came up with the formula and I came here to see if someone could explain it. The solution seemed obvious so i didn't see what the deal was. Thanks for not explaning anything and being a dick dex.
 
Everything you need to know to get the formula, you learned in Algebra II! (really!)

Probably the easiest place to begin is to figure out how to express, algebraically, the notion that two chords of a circle are equal in length. You pick how to represent the lines algebraically.
 

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