You do know the multiplicative property of the Legendre symbol, right? (That ).
Also, .
Show that if is a quadratic residue and then is a quadratic residue .
I am not sure where to go with this proof, I started with:
because is a quadratic residue.
Stumped right here.
Then I thought maybe using Legendre's symbols would be better.
because is a quadratic residue
So I have two starting points and no finish line in sight.
Thanks in advance for any help.
But not sure where to go to show that