Question 887665
How do you mean, "how would you solve..."?  You have an equation of a circle; nothing more.  What do you want from it?  You could arrange it solved for x or you could arrange it solved for y.  For either of those, use the number properties that you are learning.


The equation is better shown as {{{x^2+y^2=2}}}.  You can put it into function form:
{{{y^2=-x^2+2}}}
{{{y=sqrt(-x^2+2)}}}
{{{highlight(y=sqrt(2-x^2))}}}


If this must stay within real numbers, then the acceptable values for x is the set  {{{-sqrt(2)<x<sqrt(2)}}}.