By pythagoras theorem, any point that has the value [tex]\sqrt{x^2+y^2}=2[/tex] is 2 units away from the origin, or point (0,0).
To make you life simpler, if x or y = 0, then (tex)sqrt(x^2+y^2)=2(/tex) simply becomes [tex]x=\pm2[/tex] or [tex]y=\pm2[/tex]
