x2 + y2 =
x2 + y2 = 5
x2 + y2 = 10
x2 + y2 = 25
x² + y² = 81.
x² + y² = 4.
x2 + y2 = 81
x2 + y2 = 16
x2 + y2 = 49
The equation of circle is (x−h)^2+(y−k)^2 = r^2, where h,k is the center of circle and r is the radius of circle. so, according to question center is origin and radius is 10, therefore, equation of circle is x^2 + y^2 = 100
x² + y² = 81.
x² + y² = 4.
x2 + y2 = 81
x2 + y2 = 64
x2 + y2 = 16
9
x2 + y2 = 49
x2 + y2 = r2, where r is the radius.
It is x2 + y2 = 4
A unit circle is a circle of radius 1. If it's center is at the origin of an xy-coordinate system, then the equation is x (squared) + y (squared) = 1
x2 + y2 = 2