Question 118
On the Cartesian plane $XOY$, draw the set of points whose coordinates satisfy
$$
\sqrt{1-x^2}+\sqrt{1-y^2}=2-x^2-y^2.
$$
$$
\sqrt{1-x^2}+\sqrt{1-y^2}=2-x^2-y^2.
$$
MathNet 2009-part-04 — 175 problems (EN–VI) Question 118
Math Olympiad Vault · MathNet 2009-part-04 — 175 problems (EN–VI)