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Forum Name: This and that
Topic ID: 946
#0, A better Calculus Proof of the Pythagorean Theorem?
Posted by jmolokach on Sep-29-10 at 02:01 PM
I found the following at http://www.scribd.com/doc/30552/A-Calculus-Proof-of-the-Pythagorean-Theorem

I do not know the author, but it seems to me a strong counterexample to the Pythagorean Proposition:

<a title="View A Calculus Proof of the Pythagorean Theorem on Scribd" href="http://www.scribd.com/doc/30552/A-Calculus-Proof-of-the-Pythagorean-Theorem"; style="margin: 12px auto 6px auto; font-family: Helvetica,Arial,Sans-serif; font-style: normal; font-variant: normal; font-weight: normal; font-size: 14px; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none; display: block; text-decoration: underline;">A Calculus Proof of the Pythagorean Theorem</a> <object id="doc_419953862916615" name="doc_419953862916615" height="600" width="100%" type="application/x-shockwave-flash" data="http://d1.scribdassets.com/ScribdViewer.swf"; style="outline:none;" > <param name="movie" value="http://d1.scribdassets.com/ScribdViewer.swf";> <param name="wmode" value="opaque"> <param name="bgcolor" value="#ffffff"> <param name="allowFullScreen" value="true"> <param name="allowScriptAccess" value="always"> <param name="FlashVars" value="document_id=30552&access_key=8gu5a2firfg4u&page=1&viewMode=list"> <embed id="doc_419953862916615" name="doc_419953862916615" src="http://d1.scribdassets.com/ScribdViewer.swf?document_id=30552&access_key=8gu5a2firfg4u&page=1&viewMode=list"; type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" height="600" width="100%" wmode="opaque" bgcolor="#ffffff"></embed> </object>


#1, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by alexb on Sep-29-10 at 02:25 PM
In response to message #0
>I do not know the author, but it seems to me a strong
>counterexample to the Pythagorean Proposition:

You mean a counterexample to Elisha Loomis' opinion?

Yeap, fine.


#2, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by jmolokach on Sep-29-10 at 02:27 PM
In response to message #0
sorry forgot to change the html code:

I found the following at http://www.scribd.com/doc/30552/A-Calculus-Proof-of-the-Pythagorean-Theorem

I do not know the author, but it seems to me a strong counterexample to the Pythagorean Proposition:

A Calculus Proof of the Pythagorean Theorem


#3, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by jmolokach on Sep-29-10 at 02:27 PM
In response to message #0
OK apparently the html is not working, or I am missing something but the link still works... could this be proof #89?

By the way I have to mention again I do not know the author of this page, but he seems to have gone to great lengths to defend his use of Calculus...


#5, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by alexb on Sep-29-10 at 02:33 PM
In response to message #3
1. I have two calculus proofs on my page.
2. I have no patience with your link. He used calculus to argue that

F(x,y) ≥ 0

while it is obvious from the definition.

I am not wedded to the Pythagorean theorem or to its proofs. Sometimes I err in my selections, perhaps, even often so, but what I am on lookout for is elegance not a refutation of Elisha Loomis' opinions. So, no, this is not going to be proof #89.


#6, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by jmolokach on Sep-29-10 at 03:32 PM
In response to message #5
>1. I have two calculus proofs on my page.

Yes, sir. I realize that. I did not mean to sound like you were lock-in-step with Loomis.

>2. I have no patience with your link. He used calculus to
>argue that
>
>F(x,y) ≥ 0
>
>while it is obvious from the definition.

I need help on this. Did you mean that the statement was unnecessary, or that it depends on the PT and creates a circular argument?

>
>I am not wedded to the Pythagorean theorem or to its proofs.
>Sometimes I err in my selections, perhaps, even often so,
>but what I am on lookout for is elegance not a refutation of
>Elisha Loomis' opinions. So, no, this is not going to be
>proof #89.

Sorry, I jumped the gun on this a little and was wrong to suggest that you post this to your page as proof #89. I apologize if I offended you. Ironically, I am still "wedded" to my own Calculus proof and hope somehow to argue its validity. I suppose I am stubborn in that regard. It was my intention to look at this link as an improvement somewhat in my own thinking.

I am still having a hard time with the reasoning behind why my own calculus proof is circular. I suppose I am blind to some big assumptions I made on that, or else I am ignorant of the circularity somewhere. Rest assured, I am trying.

Also, I did post that proof on mathforum... And the discussion there got me to thinking that I should not assume that slope of a line can be gained apart from the PT. Am I headed in the right direction?

Again you have been very kind to respond to my barrage of posts recently. Thanks for your correspondence and commentary.


#8, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by alexb on Sep-29-10 at 03:43 PM
In response to message #6
>>2. I have no patience with your link. He used calculus to
>>argue that
>>
>>F(x,y) ¡Ư 0
>>
>>while it is obvious from the definition.
>
>I need help on this. Did you mean that the statement was
>unnecessary, or that it depends on the PT and creates a
>circular argument?

No, it is exactly as I wrote. He defined F(x, y) which is by defintion is not negative and then wasted a page proving that it is so by using calculus. There is not circularity but a waste.

>Also, I did post that proof on mathforum... And the
>discussion there got me to thinking that I should not assume
>that slope of a line can be gained apart from the PT.

Just continue the discussion there.


#7, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by alexb on Sep-29-10 at 03:40 PM
In response to message #3
HTML works fine, except you should use square and not angular brackets.

#4, RE: A better Calculus Proof of the Pythagorean Theorem?
Posted by jmolokach on Sep-29-10 at 02:27 PM
In response to message #0
This appears to have come from a book entitled "The Pythagorean Theorem:
Crown Jewel of Mathematics"

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