ACOPS- NT problem
-
bristy1588
- Posts:92
- Joined:Sun Jun 19, 2011 10:31 am
Find all $x$ such that $ x^2+ 2$ is a prime.
Bristy Sikder
Re: ACOPS- NT problem
It must say $x$ prime as well. Otherwise it is impossible to find. And then $x=3$ is the only solution since otherwise $x^2+2\equiv1+2\equiv0\pmod3$
One one thing is neutral in the universe, that is $0$.
Re: ACOPS- NT problem
Umm...actually $x=1,3$. And yeah, mod 3 will do the trick.
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.
Re: ACOPS- NT problem
No. 
When you say $x$ is prime.
When you say $x$ is prime.One one thing is neutral in the universe, that is $0$.