need some help

**jackie** · November 15th 2008, 03:07 PM

Thank you very much ThePerfectHacker. Oops, I accidentally deleted my post, was trying to edit my proof. Anyway, many thanks to you, ThePerfectHacker

**ThePerfectHacker** · November 15th 2008, 03:32 PM

Originally Posted by jackie

I'm not sure about my proof because it seems that I didn't show both ways because this is an iff statement.

One side of the proof is obvious. If $x^4 \equiv a$ is solvable then $(x^2)^2 \equiv a$ and so $x^2\equiv a$ is solvable.

**jackie** · November 15th 2008, 03:41 PM

Thank you ThePerfectHacker. So, what I did was irrelevant and not really related to the proof?

**ThePerfectHacker** · November 15th 2008, 04:15 PM

Originally Posted by jackie

Thank you ThePerfectHacker. So, what I did was irrelevant and not really related to the proof?

You proved if $x^2 \equiv a(\bmod p)$ has a solution then $x^4 \equiv a(\bmod p)$ .

Thread: need some help