Answer:
x² + y² = 1
Explanation:
A circle is the locus of a point such that its distance from a fixed point (known as the origin) is always constant. The general equation of a circle is given as:

Where (h, k) is the center of the circle and r is the radius of the circle.
Given that the plane is 1 unit from the point (0,0). Therefore the radius of the circle is 1 unit and the center of the circle is (0, 0). Therefore the equation of the circle is:
