- #1

MathematicalPhysicist

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Not sure, but from the definition we have 1=XY/2 and X^2+Y^2= Z^2, so by adding and substracting 4 (2XY) I get (X+-Y)^2 = Z^2+-4

multiply them both to get: Z^4-2^4= (X^2-Y^2)^2

I would like to show that X^2-Y^2 is my odd number, but don't see how.

Thanks for any hints.