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Simple Proof of Fermats Last Theorem: Is There Any Mistake Here? (github.com)
4 points by Mi_Ka_ 3500 days ago
3 comments

thanks a lot for sharing these links. Specially this one- http://fermatslasttheorem.blogspot.com/2005/08/another-false...

I understand, I need to prove that- cos θ is irrational for all θ, where 60<θ<90. Which is not actually true.

Fermat's Last Theorem is easily demonstrated using the binomial theorem - simple algebra. It is dismissed as a proof because most fail to "see" or "understand" variables - particularly mathematicians. Fermat gave us a hint as to his "demonstration" by where he wrote his comment ( https://en.wikipedia.org/wiki/Diophantus_II.VIII ). The difference of two squares can - in some cases - be a square - Pythagorean triples! The difference (or sum) of two integers raised to a power greater than two - nope.
How does cos(theta) produce irrational values for 60 deg <= theta <= 90 deg?
That is what I knew. For example- cos 75 = (√2(√3 – 1))/4

For testing you can visit here- http://www.webconversiononline.com/trigonometry-calculator.a...

cosine is a continuous function. Rationals are dense in reals etc. eg, arccos(1/3)
Yes, arccos(1/3) = 70.5287794 degrees
The important point is that

cos(arcos(1/3)) = cos(70.5287794... degrees) = 1/3

that is a rational value.