Terry M
Posts:
15
Registered:
4/26/12


Re: Pell type equations
Posted:
Apr 29, 2012 10:48 AM


My deductions so far...
of a², b², c² and d²
no solutions if exactly three of these = 1 mod 8
if exactly one of a² and b² = 1 mod 8 and exactly one of c² and d² = 1 mod 8, then the two remaining must be equal mod 8
e.g if a² = 1 mod 8 and c²=1 mod 8 then if b² <> d² mod 8 there are no solutions.

