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Conferences  The CTK Exchange This and that |
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Discussion Topic |
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Last Updated Date/Author |
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One equal zero
Do you know that:
http://www.dodaj.rs/f/3x/h0/ruwKW1L/oneeqzero.png
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nikolinv |
May-21-11 03:50 PM
by alexb |
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"Proof of the Cosine Rule completely independent of the PT"
Alex,
At your page:
http://www.cut-the-knot.org/pythagoras/cosine.shtml
You mention "I'll be extremely curious to lea... |
jmolokach |
May-16-11 04:25 PM
by alexb |
14
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divisibility
if (A + mX)/(5 or 10)is divisible by m, then A is divisible by m.
also if (A - mX)/(5 or 10)is divisible by m, then A is ... |
ranjitr303 |
May-11-11 01:38 PM
by alexb |
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Is Every Parallelogram Rectangle?
Let a and b denote sides, d1 and d2 denote diagonals of a parallelogram ABCD. Triangle ABC (with sides a, b and d1) and triangle ABD (with s... |
nikolinv |
May-09-11 07:24 PM
by alexb |
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How old is John, how old is Maria?
Peter: How did you get such an ugly polynomial f(x) with so many unknown coefficients? It looks terrible!
Paul: This is polynomial wi... |
nikolinv |
Apr-26-11 07:09 PM
by alexb |
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Determinants
Alex,
I would like to post my determinant problem .
http://www.cut-the-knot.org/arithmetic/algebra/Determinant.shtml
Let ... |
C Reineke |
Apr-25-11 12:37 PM
by alexb |
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Pythagorean theorem and determinants
The Pythagorean theorem as an application of the determinant properties in the plane:
http://w3.romascuola.net/gspes/unitary.html %... |
gaespes |
Apr-06-11 11:23 AM
by gaespes |
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Calculus Proof for Pythagorean Theorem (again)
[View All]
Thanks to Alexander Giventhal at Berkley, I am giving yet another shot at proving the Pythagorean Theorem using Calculus. I have been told that my ... |
jmolokach |
Apr-05-11 06:46 AM
by alexb |
43
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Calculating raw probabilities
I am presently using a skip/shift-of-one transposition equidistant letter sequence in an effort to decrypt possible intentionally placed letter... |
drferris68 |
Apr-03-11 10:07 PM
by drferris68 |
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some fun stuff
On Impossible Figures {or On Evans' (Most) Impossible Triangle}
Regardless of the type or number of arguments that can be leveled at a ... |
hewman123 |
Apr-01-11 09:23 AM
by hewman123 |
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angle trisection
its interesting that although we cannot trisect the angle, we are able to provide a diagram of what a successfully trisected angle would like if we ... |
hewman123 |
Apr-01-11 00:32 AM
by hewman123 |
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A question
[View All]
Is it possible to algebraically derive the law of cosines from the law of sines, without recourse to the Pythagorean Theorem?... |
jmolokach |
Mar-23-11 11:30 AM
by jmolokach |
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Shoestring Proof of the Pythagorean Theorem
[View All]
I think this is somewhat simpler than what I have written before.
Occam's Razor or just a restatement of Proof 4? I think this is slightly d... |
jmolokach |
Mar-20-11 11:30 AM
by gaespes |
24
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Equivalence of the Law of Sines, PT, and Law of Cosines
Here's the link to the paper.
https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0Bwc0zPMWJ9wqYmFmNzdlND... |
jmolokach |
Mar-07-11 10:00 AM
by jmolokach |
5
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distance vs orthogonality vs choice
Since the mid-seventies, during my first university studies, I was unsatisfied with the way of introducing the metric in the usual treatments of t... |
gaespes |
Feb-18-11 07:22 PM
by gaespes |
12
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Trigonometric Proof of the Pythagorean Theorem
http://www.cut-the-knot.org/pythagoras/TrigProof.shtml
Dear Alex,
it is very easy to derive the subtraction formulas from Euler%... |
C Reineke |
Feb-15-11 04:06 PM
by jmolokach |
4
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A complex number approach...
In a recent discussion during a high school math class, my students learned that a + bi multiplied by it's conjugate gives the real number a^2... |
jmolokach |
Feb-09-11 07:01 PM
by gaespes |
20
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PT by area sweeping
Here is another approach, based on a couple of simple ideas about flow across a boundary. First, consider a triangle moving smoothly around in th... |
mr_homm |
Jan-24-11 12:36 PM
by alexb |
2
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Nondifferentiability without limits
I found this link for "derivatives without limits"
http://www.cut-the-knot.org/wiki-math/index.php?n=Calculus.DerivativesWithou... |
jmolokach |
Jan-20-11 12:06 PM
by alexb |
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Calculus Proof of PT
The late Edwin Moise was co-author of my first Geometry textbook back in 9th grade. He later wrote a fascinating text, "Elementary Geometry from a... |
sbrodie |
Jan-15-11 08:54 AM
by jmolokach |
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An inequality of Archimedes (and a claim...)
Alex, I would like to thank you for characterizing me as a "devoted Pythagorean."
So now it seems I have shifted my focus from the Pythagor... |
jmolokach |
Jan-11-11 01:14 PM
by jmolokach |
4
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to find log of a number
i have found that the mantissa(M)for a number X can be approximated by a simple formula
M= y(19-y)
where y= X written such that 3>y%... |
ranjitr303 |
Jan-10-11 01:14 PM
by ranjitr303 |
0
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Age old debate
Doing these PT proofs has got me thinking about the amalgamation of geometry and algebra... For instance... The integral from -1 to 1 of 1/x ... g... |
jmolokach |
Dec-29-10 04:20 AM
by jmolokach |
13
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Calculus Proof of PT
The recent posting of a "Calculus-based" proof of PT draws me into this discussion. I'm afraid I am still skeptical. The problem is deeper than ... |
sbrodie |
Dec-28-10 11:58 PM
by alexb |
3
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Variation of proof #43 - Pythagorean Theorem
OK, here is yet another one I have done. I have not seen anything like this exactly on your page, but I feel it is a variation somewhat of proof ... |
John Molokach  |
Dec-23-10 06:05 PM
by jmolokach |
7
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Parallelogram Proof of the PT
I seem to be obsessed with these... here is another...
https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid%3... |
jmolokach |
Dec-23-10 08:21 AM
by jmolokach |
2
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Models of the regular solids
I am looking for nice models of the 5 regular solids. Wood would be great but nice plastic is OK. Any ideas where I can buy some. I've done a lot... |
dwstout |
Dec-21-10 04:45 PM
by alexb |
3
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prime finder
take m as a number such that (m-1)and (m+1) are prime. eg: 4, 6, 12, etc.
therefore either (n*m +1) and/or (n*m -1%2... |
ranjitr303 |
Dec-02-10 07:44 AM
by C Reineke |
1
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circle in circle
how many circles of radius r can fit in a bigger circle of radius R ?
ans: let n denote the maximum number of circles that can fit in the big... |
ranjitr303 |
Nov-28-10 08:54 AM
by jmolokach |
7
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Proof #23 using Wolfram Alpha
I have been having fun using Wolfram Alpha. This is likely an identical manifestation of proof #23 of the Pythagorean Theorem, but thanks to Wolf... |
jmolokach |
Nov-22-10 07:35 PM
by alexb |
9
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