30 Apr
2006
30 Apr
'06
12:27 p.m.
David Wilson wrote:
Yes and the proof is surprisingly simple. Let x = 1, y = 0. Works for noninteger D as well.
Oops. Yes, of course. Thanks. I left out the word "nontrivial". Maybe I'll get it right this time: For D > 0, D an integer, not a square, x^2 - Dy^2 = 1 has a solution in integers x, y, with y > 0. John Robertson